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Transcript of PC78MR-6_SEBM030601
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00-1
MACHINE MODEL SERIAL NUMBER
PC78MR-6 1001 and up
This shop manual may contain attachments and optional equipment that are not available in yourarea. Please consult your local Komatsu distributor for those items you may require. Materials andspecifications are subject to change without notice.
PC78MR-6 mounts the S4D95LE-3-A engine.For details of the engine, see the 95-3 Series Engine Shop Manual.
SEBM030601
2003All Rights ReservedPrinted in Japan 12-03(02)
(1)
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00-2 PC78MR-6
CONTENTS
No. of page
01 GENERAL ................................................................................................................01-1
10 STRUCTURE AND FUNCTION, MAINTENANCE STANDARD......................................................................10-1
20 TESTING AND ADJUSTING .......................................................................20-1
30 DISASSEMBLY AND ASSEMBLY ..........................................................30-1
90 OTHERS ....................................................................................................................90-1
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PC78MR-6 00-2-1
The affected pages are indicated by the use of thefollowing marks. It is requested that necessaryactions be taken to these pages according to thetable below.
Pages having no marks are those previously revisedor made aditions.
Mark Indication Action required
Q Page to be newly added Add
q Page to be replaced Replace
( ) Page to be deleted Discard
LIST OF REVISED PAGESMark Page Revision number
q 00-1 (1)00-2
Q 00-2-1 (1)Q 00-2-2 (1)Q 00-2-3 (1)
00-300-400-500-600-700-800-900-1000-1100-1200-1300-1400-1500-1600-1700-1800-1900-2000-2100-22
01-101-201-301-401-501-601-701-801-9
q 10-1 (1)10-210-310-410-5
10-610-710-810-910-1010-1110-1210-1310-1410-1510-1610-1710-18
q 10-19 (1)10-2010-2110-2210-2310-2410-2510-2610-2710-2810-2910-3010-3110-32
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00-2-2 PC78MR-6
20-120-220-320-420-520-620-720-820-920-1020-1120-1220-1320-1420-1520-10120-10220-10320-10420-10520-10620-10720-10820-10920-11020-11120-11220-11320-11420-11520-11620-11720-11820-11920-12020-12120-12220-12320-12420-12520-12620-12720-12820-12920-13020-13120-13220-13320-13420-13520-136
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q 20-257 (1)20-25820-25920-26020-30120-30220-30320-30420-30520-30620-30720-30820-30920-31020-31120-31220-31320-31420-31520-31620-31720-31820-31920-32020-32120-32220-32320-32420-40120-40220-50120-50220-50420-50520-50620-50720-50820-50920-51020-51120-51220-51320-51420-515
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20-80820-80920-81020-81120-81220-81320-81420-81520-81620-81720-81820-81920-82020-82120-82220-82320-82420-82520-82620-82720-82820-82920-83020-83120-83220-83320-83420-83520-83620-83720-83820-83920-84020-84120-84220-84320-84420-84520-84620-84720-84820-84920-85020-85120-85220-85320-85420-85520-85620-85720-858
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PC78MR-6 00-2-3
20-85920-86020-86120-90120-90220-90320-90420-90520-90620-90720-90820-90920-91020-91120-91220-91320-91420-91520-91620-91720-91820-91920-92020-92120-92220-92320-92420-92520-92620-92720-92820-929
30-130-230-330-430-530-630-730-830-930-1030-1130-1230-1330-1430-1530-1630-1730-18
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30-1930-2030-2130-2230-2330-2430-2530-2630-2730-2830-2930-3030-3130-3230-3330-3430-3530-3630-3730-3830-3930-4030-4130-4230-4330-4430-4530-4630-4730-4830-4930-5030-5130-5230-5330-5430-5530-5630-5730-5830-5930-6030-6130-6230-6330-6430-6530-6630-6730-68
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q 90-1 (1)q 90-3 (1)q 90-5 (1)q 90-7 (1)Q 90-9 (1)Q 90-11 (1)Q 90-13 (1)
Mark Page Revision number Mark PageRevision number Mark Page
Revision number
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SAFETY SAFETY NOTICE
00-3
SAFETYSAFETY NOTICE
IMPORTANT SAFETY NOTICE
Proper service and repair is extremely important for safe machine operation. The service andrepair techniques recommended by Komatsu and described in this manual are both effectiveand safe. Some of these techniques require the use of tools specially designed by Komatsu forthe specific purpose.
To prevent injury to workers, the symbol is used to mark safety precautions in this manual.The cautions accompanying these symbols should always be followed carefully. If any danger-ous situation arises or may possibly arise, first consider safety, and take the necessary actionsto deal with the situation.
GENERAL PRECAUTIONS
Mistakes in operation are extremely dangerous.Read the Operation and Maintenance Manual care-fully BEFORE operating the machine.1. Before carrying out any greasing or repairs, read
all the precautions given on the decals which arefixed to the machine.
2. When carrying out any operation, alwayswear safety shoes and helmet. Do not wearloose work clothes, or clothes with buttonsmissing. Always wear safety glasses when hitting
parts with a hammer. Always wear safety glasses when grinding
parts with a grinder, etc.3. If welding repairs are needed, always have a
trained, experienced welder carry out the work.When carrying out welding work, always wearwelding gloves, apron, hand shield, cap andother clothes suited for welding work.
4. When carrying out any operation with two ormore workers, always agree on the operatingprocedure before starting. Always inform yourfellow workers before starting any step of theoperation. Before starting work, hang UNDERREPAIR signs on the controls in the operator'scompartment.
5. Keep all tools in good condition and learn thecorrect way to use them.
6. Decide a place in the repair workshop to keeptools and removed parts. Always keep the toolsand parts in their correct places. Always keepthe work area clean and make sure that there isno dirt or oil on the floor. Smoke only in the areasprovided for smoking. Never smoke while work-ing.
PREPARATIONS FOR WORK
7. Before adding oil or making any repairs, park themachine on hard, level ground, and block thewheels or tracks to prevent the machine frommoving.
8. Before starting work, lower blade, ripper, bucketor any other work equipment to the ground. Ifthis is not possible, insert the safety pin or useblocks to prevent the work equipment from fall-ing. In addition, be sure to lock all the controllevers and hang warning signs on them.
9. When disassembling or assembling, support themachine with blocks, jacks or stands beforestarting work.
10.Remove all mud and oil from the steps or otherplaces used to get on and off the machine.Always use the handrails, ladders or steps whengetting on or off the machine. Never jump on oroff the machine. If it is impossible to use thehandrails, ladders or steps, use a stand to pro-vide safe footing.
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SAFETY SAFETY NOTICE
00-4
PRECAUTIONS DURING WORK
11.When removing the oil filler cap, drain plug orhydraulic pressure measuring plugs, loosenthem slowly to prevent the oil from spurting out.Before disconnecting or removing componentsof the oil, water or air circuits, first remove thepressure completely from the circuit.
12.The water and oil in the circuits are hot when theengine is stopped, so be careful not to getburned.Wait for the oil and water to cool before carry-ing out any work on the oil or water circuits.
13.Before starting work, remove the leads from thebattery. Always remove the lead from the nega-tive () terminal first.
14.When raising heavy components, use a hoist orcrane.
Check that the wire rope, chains and hooks arefree from damage.Always use lifting equipment which has amplecapacity.Install the lifting equipment at the correct places.Use a hoist or crane and operate slowly to pre-vent the component from hitting any other part.Do not work with any part still raised by the hoistor crane.
15.When removing covers which are under internalpressure or under pressure from a spring,always leave two bolts in position on oppositesides. Slowly release the pressure, then slowlyloosen the bolts to remove.
16.When removing components, be careful not tobreak or damage the wiring. Damaged wiringmay cause electrical fires.
17.When removing piping, stop the fuel or oil fromspilling out. If any fuel or oil drips onto the floor,wipe it up immediately. Fuel or oil on the floorcan cause you to slip, or can even start fires.
18.As a general rule, do not use gasoline to washparts. In particular, use only the minimum ofgasoline when washing electrical parts.
19.Be sure to assemble all parts again in their origi-nal places.Replace any damaged parts with new parts. When installing hoses and wires, be sure
that they will not be damaged by contactwith other parts when the machine is beingoperated.
20.When installing high pressure hoses, make surethat they are not twisted. Damaged tubes aredangerous, so be extremely careful when install-ing tubes for high pressure circuits. Also, checkthat connecting parts are correctly installed.
21.When assembling or installing parts, always usethe specified tightening torques. When installingprotective parts such as guards, or parts whichvibrate violently or rotate at high speed, be par-ticularly careful to check that they are installedcorrectly.
22.When aligning two holes, never insert your fin-gers or hand. Be careful not to get your fingerscaught in a hole.
23.When measuring hydraulic pressure, check thatthe measuring tool is correctly assembled beforetaking any measurements.
24.Take care when removing or installing the tracksof track-type machines.When removing the track, the track separatessuddenly, so never let anyone stand at eitherend of the track.
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FOREWORD GENERAL
00-5
FOREWORDGENERALThis shop manual has been prepared as an aid to improve the quality of repairs by giving the serviceman anaccurate understanding of the product and by showing him the correct way to perform repairs and make judge-ments. Make sure you understand the contents of this manual and use it to full effect at every opportunity.
This shop manual mainly contains the necessary technical information for operations performed in a serviceworkshop. For ease of understanding, the manual is divided into the following chapters; these chapters are fur-ther divided into the each main group of components.
STRUCTURE AND FUNCTIONThis section explains the structure and function of each component. It serves not only to give an under-standing of the structure, but also serves as reference material for troubleshooting.In addition, this section may contain hydraulic circuit diagrams, electric circuit diagrams, and mainte-nance standards.
TESTING AND ADJUSTINGThis section explains checks to be made before and after performing repairs, as well as adjustments tobe made at completion of the checks and repairs.Troubleshooting charts correlating "Problems" with "Causes" are also included in this section.
DISASSEMBLY AND ASSEMBLYThis section explains the procedures for removing, installing, disassembling and assembling each com-ponent, as well as precautions for them.
MAINTENANCE STANDARDThis section gives the judgment standards for inspection of disassembled parts.The contents of this section may be described in STRUCTURE AND FUNCTION.
OTHERSThis section mainly gives hydraulic circuit diagrams and electric circuit diagrams.In addition, this section may give the specifications of attachments and options together.
NOTICE
The specifications contained in this shop manual are subject to change at any time and without anyadvance notice. Use the specifications given in the book with the latest date.
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FOREWORD HOW TO READ THE SHOP MANUAL
00-6
HOW TO READ THE SHOP MANUAL
VOLUMESShop manuals are issued as a guide to carrying outrepairs. They are divided as follows:
Chassis volume: Issued for every machine modelEngine volume: Issued for each engine seriesElectrical volume: Attachments volume:
These various volumes are designed to avoid dupli-cating the same information. Therefore, to deal withall repairs for any model , it is necessary that chas-sis, engine, electrical and attachment volumes beavailable.
DISTRIBUTION AND UPDATINGAny additions, amendments or other changes will besent to KOMATSU distributors. Get the most up-to-date information before you start any work.
FILING METHOD1. See the page number on the bottom of the page.
File the pages in correct order.2. Following examples show how to read the page
number.Example 1 (Chassis volume):
10 - 3
Item number (10. Structure andFunction)Consecutive page number for eachitem.
Example 2 (Engine volume):
12 - 5
Unit number (1. Engine)Item number (2. Testing and Adjust-ing)Consecutive page number for eachitem.
3. Additional pages: Additional pages are indicated by a hyphen (-) and number after the page number. File as in the example.Example:10-410-4-110-4-210-5
REVISED EDITION MARK
When a manual is revised, an edit ion mark(123....) is recorded on the bottom of the pages.
REVISIONS
Revised pages are shown in the LIST OF REVISEDPAGES next to the CONTENTS page.
SYMBOLS
So that the shop manual can be of ample practicaluse, important safety and quality portions aremarked with the following symbols.
Symbol Item Remarks
SafetySpecial safety precautionsare necessary when per-forming the work.
s
Caution
Special technical precau-tions or other precautionsfor preserving standardsare necessary when per-forming the work.
4 Weight
Weight of parts of sys-tems. Caution necessarywhen selecting hoistingwire, or when working pos-ture is important, etc.
3
Tighteningtorque
Places that require specialattention for the tighteningtorque during assembly.
2 CoatPlaces to be coated withadhesives and lubricants,etc.
5 Oil, waterPlaces where oil, water orfuel must be added, andthe capacity.
6 DrainPlaces where oil or watermust be dra ined, andquantity to be drained.
} Each issued as onevolume to cover allmodels
12-20312-203-112-203-212-204
Added pages
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FOREWORD HOISTING INSTRUCTIONS
00-7
HOISTING INSTRUCTIONS
HOISTING
Heavy parts (25 kg or more) must be liftedwith a hoist, etc. In the DISASSEMBLYAND ASSEMBLY section, every partweighing 25 kg or more is indicated clearlywith the symbol 4
If a part cannot be smoothly removed from themachine by hoisting, the following checksshould be made:1) Check for removal of all bolts fastening the
part to the relative parts.2) Check for existence of another part causing
interference with the part to be removed.
WIRE ROPES1) Use adequate ropes depending on the
weight of parts to be hoisted, referring tothe table below:
Wire ropes(Standard "Z" or "S" twist ropes
without galvanizing)
The allowable load value is estimated to be one-sixth or one-seventh of the breaking strength ofthe rope used.
2) Sling wire ropes from the middle portion of thehook.
Slinging near the edge of the hook may causethe rope to slip off the hook during hoisting, anda serious accident can result. Hooks have max-imum strength at the middle portion.
3) Do not sling a heavy load with one rope alone,but sling with two or more ropes symmetricallywound onto the load. Slinging with one rope may cause turning
of the load during hoisting, untwisting ofthe rope, or slipping of the rope from itsoriginal winding position on the load, whichcan result in a dangerous accident.
4) Do not sling a heavy load with ropes forming awide hanging angle from the hook.When hoisting a load with two or more ropes,the force subjected to each rope will increasewith the hanging angles. The table belowshows the variation of allowable load kN {kg}when hoisting is made with two ropes, each ofwhich is allowed to sling up to 9.8 kN {1000 kg}vertically, at various hanging angles.When two ropes sling a load vertically, up to19.6 kN {2000 kg} of total weight can be sus-pended. This weight becomes 9.8 kN {1000 kg}when two ropes make a 120 hanging angle.On the other hand, two ropes are subjected toan excessive force as large as 39.2 kN {4000kg} if they sling a 19.6 kN {2000 kg} load at alifting angle of 150.
Rope diameter Allowable load
mm kN tons
1011.512.514161820
22.430405060
9.813.715.721.627.535.343.154.998.1176.5274.6392.2
1.01.41.62.22.83.64.45.6
10.018.028.040.0
SAD00479
41%71%79%88%100%
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FOREWORD METHOD OF DISASSEMBLING, CONNECTING PUSH-PULL TYPE COUPLER
00-8
METHOD OF DISASSEMBLING, CONNECTING PUSH-PULL TYPE COUPLER
Before carrying out the following work, releasethe residual pressure from the hydraulic tank.For details, see TESTING AND ADJUSTING,Releasing residual pressure from hydraulictank.
Even if the residual pressure is released fromthe hydraulic tank, some hydraulic oil flows outwhen the hose is disconnected. Accordingly,prepare an oil receiving container.
Disconnection1) Release the residual pressure from the hydrau-
l ic tank. For detai ls , see TESTING ANDADJUSTING, Releasing residual pressure fromhydraulic tank.
2) Hold adapter (1) and push hose joint (2) intomating adapter (3). (See Fig. 1) The adapter can be pushed in about 3.5
mm. Do not hold rubber cap portion (4).
3) After hose joint (2) is pushed into adapter (3),press rubber cap portion (4) against (3) until itclicks. (See Fig. 2)
4) Hold hose adapter (1) or hose (5) and pull it out.(See Fig. 3) Since some hydraulic oil flows out, prepare
an oil receiving container.
Connection1) Hold hose adapter (1) or hose (5) and insert it in
mating adapter (3), aligning them with eachother. (See Fig. 4) Do not hold rubber cap portion (4).
2) After inserting the hose in the mating adapterperfectly, pull it back to check its connectingcondition. (See Fig. 5) When the hose is pulled back, the rubber
cap portion moves toward the hose about3.5 mm. This does not indicate abnormality,however.
Type 1
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FOREWORD METHOD OF DISASSEMBLING, CONNECTING PUSH-PULL TYPE COUPLER
00-9
Type 2 Type 3D
isa
ssem
bly
1) Hold the mouthpiece of the tightening portionand push body (2) in straight until sliding pre-vention ring (1) contacts contact surface a ofthe hexagonal portion at the male end.
2) Hold in the condition in Step 1), and turnlever (4) to the right (clockwise).
3) Hold in the condition in Steps 1) and 2), andpull out whole body (2) to disconnect it.
1) Hold the mouthpiece of the tightening portionand push body (2) in straight until sliding pre-vention ring (1) contacts contact surface a ofthe hexagonal portion at the male end.
2) Hold in the condition in Step 1), and pushuntil cover (3) contacts contact surface a ofthe hexagonal portion at the male end.
3) Hold in the condition in Steps 1) and 2), andpull out whole body (2) to disconnect it.
Conn
ectio
n
Hold the mouthpiece of the tightening portionand push body (2) in straight until sliding pre-vention ring (1) contacts contact surface a ofthe hexagonal portion at the male end to con-nect it.
Hold the mouthpiece of the tightening portionand push body (2) in straight until sliding pre-vention ring (1) contacts contact surface a ofthe hexagonal portion at the male end to con-nect it.
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FOREWORD COATING MATERIALS
00-10
COATING MATERIALS
The recommended coating materials such as adhesives, gasket sealants and greases used for disassemblyand assembly are listed below.
For coating materials not listed below, use the equivalent of products shown in this list.
Category Komatsu code Part No. Q'ty Container Main applications, featuresr
Adhesives
LT-1A 790-129-9030 150 g Tube Used to prevent rubber gaskets,
rubber cushions, and cock plugfrom coming out.
LT-1B 790-129-9050 20 g(2 pcs.)Polyethylene
container
Used in places requiring an imme-diately effective, strong adhesive.Used for plastics (except polyeth-ylene, polyprophylene, tetrafluor-oethlene and vinyl chlor ide),rubber, metal and non-metal.
LT-2 09940-00030 50 g Polyethylenecontainer
Features: Resistance to heat andchemicals
Used for anti-loosening and seal-ant purpose for bolts and plugs.
LT-3
790-129-9060(Set of
adhesive and hardening
agent)
Adhesive:1 kg
Hardening
agent:500 g
Can
Used as adhesive or sealant formetal, glass and plastic.
LT-4 790-129-9040 250 g Polyethylenecontainer Used as sealant for machined
holes.
HoltzMH 705 790-126-9120 75 g Tube
Used as heat-resisting sealant forrepairing engine.
Three bond1735 790-129-9140 50 g
Polyethylenecontainer
Quick hardening type adhesive Cure time: within 5 sec. to 3 min. Used mainly for adhesion of met-
als, rubbers, plastics and woods.
Aron-alpha201 790-129-9130 2 g
Polyethylenecontainer
Quick hardening type adhesive Quick cure type (max. strength af-
ter 30 minutes) Used mainly for adhesion of rub-
bers, plastics and metals.
Loctite648-50 79A-129-9110 50 cc
Polyethylenecontainer
Resistance to heat, chemicals Used at joint portions subject to
high temperatures.
Gasketsealant
LG-1 790-129-9010 200 g Tube Used as adhesive or sealant for
gaskets and packing of powertrain case, etc.
LG-5 790-129-9070 1 kg Can
Used as sealant for variousthreads, pipe joints, flanges.
Used as sealant for taperedplugs, elbows, nipples of hydrau-lic piping.
LG-6 790-129-9020 200 g Tube
Features: Silicon based, resist-ance to heat, cold
Used as sealant for flange sur-face, tread.
mab Used as sealant for oil pan,final drive case, etc.
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FOREWORD COATING MATERIALS
00-11
Category Komatsu code Part No. Q'ty Container Main applications, featuresr
AdhesivesLG-7 790-129-9070 1 g Tube
Ftures: Silicon based, quick hard-ening type
Used as sealant for flywheelhousing, intake manifold, oil an,thermostat housing, etc.
Three bond1211 790-129-9090 100 g Tube
Used as heat-resisting sealant forrepairing engine.
Molybdenum disulphide lubricant
LM-G 09940-00051 60 g Can Used as lubricant for sliding por-tion (to prevent from squeaking).
LM-P 09940-00040 200 g Tube
Used to prevent seizure or scuf-fling of the thread when press fit-ting or shrink fitting.
Used as lubricant for linkage,bearings, etc.
Grease
G2-LI
SYG2-400LISYG2-350LISYG2-400LI-ASYG2-160LISYGA-160CNLI
Various Various
General purpose type
G2-CA
SYG2-400CASYG2-350CASYG2-400CA-ASYG2-160CASYGA-160CNCA
Various Various
Used for normal temperature,light load bearing at places in con-tact with water or steam.
Molybdenum disulphide lubricant
SYG2-400M400 g
(10 per case)
Belows type Used for places with heavy load
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FOREWORD STANDARD TIGHTENING TORQUE
00-12
STANDARD TIGHTENING TORQUESTANDARD TIGHTENING TORQUE TABLE (WHEN USING TORQUE WRENCH) In the case of metric nuts and bolts for which there is no special instruction, tighten to the torque given in
the table below.
TABLE OF TIGHTENING TORQUES FOR FLARED NUTS In the case of flared nuts for which there is no
special instruction, tighten to the torque given inthe table below.
Thread diameter of bolt
Width across flats
mm mm Nm kgm
68101214
1013171922
13.2 0 1.431 0 366 0 7
113 0 10177 0 19
1.35 0 0.153.2 0 0.36.7 0 0.711.5 0 118 0 2
1618202224
2427303236
279 0 30382 0 39549 0 59745 0 83927 0 103
28.5 0 339 0 456 0 6
76 0 8.594.5 0 10.5
2730333639
4146505560
1320 0 1401720 0 1902210 0 2402750 0 2903290 0 340
135 0 15175 0 20225 0 25280 0 30335 0 35
Thread diameter of bolt
Width across flats
mm mm Nm kgm
681012
10131427
7.85 0 1.9518.6 0 4.940.2 0 5.9
82.35 0 7.85
0.8 0 0.21.9 0 0.54.1 0 0.68.4 0 0.8
Thread diameter Width across flat Tightening torque
mm mm Nm kgm
1418222430333642
1924273236414655
24.5 0 4.949 0 19.6
78.5 0 19.6137.3 0 29.4176.5 0 29.4196.1 0 49245.2 0 49294.2 0 49
2.5 0 0.55 0 28 0 2
14 0 318 0 320 0 525 0 530 0 5
SAD00483
Sealing surface
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FOREWORD STANDARD TIGHTENING TORQUE
00-13
TABLE OF TIGHTENING TORQUES FOR SPLIT FLANGE BOLTS In the case of split flange bolts for which there is no special instruction, tighten to the torque given in the
table below.
TABLE OF TIGHTENING TORQUES FOR O-RING BOSS PIPING JOINTS Unless there are special instructions, tighten the O-ring boss piping joints to the torque below.
TABLE OF TIGHTENING TORQUES FOR O-RING BOSS PLUGS Unless there are special instructions, tighten the O-ring boss plugs to the torque below.
Thread diameter Width across flat Tightening torque
mm mm Nm kgm
101216
141722
65.7 0 6.8112 0 9.8279 0 29
6.7 0 0.711.5 0 128.5 0 3
Norminal No.Thread diameter Width across flat Tightening torque
mm mm Nm kgm
0203, 0405, 0610, 12
14
1420243342
Varies depending on type of connector.
34.3 0 4.993.1 0 9.8
142.1 0 19.6421.4 0 58.8877.1 0 132.3
3.5 0 0.59.5 0 114.5 0 243 0 6
89.5 0 13.5
Norminal No.Thread diameter Width across flat Tightening torque
mm mm Nm kgm
08101214161820243033364252
08101214161820243033364252
141719222427303232n36nn
7.35 0 1.4711.27 0 1.4717.64 0 1.9622.54 0 1.96
29.4 0 4.939.2 0 4.949 0 4.9
68.6 0 9.8107.8 0 14.7127.4 0 19.6151.9 0 24.5210.7 0 29.4323.4 0 44.1
0.75 0 0.151.15 0 0.15
1.8 0 0.22.3 0 0.23 0 0.54 0 0.55 0 0.57 0 1
11 0 1.513 0 2
15.5 0 2.521.5 0 333 0 4.5
-
FOREWORD STANDARD TIGHTENING TORQUE
00-14
TIGHTENING TORQUE FOR 102 ENGINE SERIES 1) BOLT AND NUTS
Use these torques for bolts and nuts (unit: mm) of Cummins Engine.
2) EYE JOINTSUse these torques for eye joints (unit: mm) of Cummins Engine.
3) TAPERED SCREWSUse these torques for tapered screws (unit: inch) of Cummins Engine.
TIGHTENING TORQUE TABLE FOR HOSES (TAPER SEAL TYPE AND FACE SEAL TYPE) Tighten the hoses (taper seal type and face seal type) to the following torque, unless otherwise specified. Apply the following torque when the threads are coated (wet) with engine oil.
Thread diameter Tightening torquemm Nm kgm
681012
10 0 224 0 443 0 6
77 0 12
1.02 0 0.202.45 0 0.414.38 0 0.617.85 0 1.22
Thread diameter Tightening torquemm Nm kgm
68101214
8 0 210 0 212 0 224 0 436 0 5
0.81 0 0.201.02 0 0.201.22 0 0.202.45 0 0.413.67 0 0.51
Thread diameter Tightening torqueinch Nm kgm
1 / 161 / 81 / 43 / 81 / 23 / 4
1
3 0 18 0 212 0 215 0 224 0 436 0 560 0 9
0.31 0 0.100.81 0 0.201.22 0 0.201.53 0 0.412.45 0 0.413.67 0 0.516.12 0 0.92
Nominal size of hose
Width across flats
Tightening torque (Nm {kgm}) Taper seal type Face seal type
Range Target Thread size (mm)Nominal thread
size - Threads per inch, Thread series
Root diameter (mm) (Reference)
02 19 35 - 63 {3.5 - 6.5} 44 {4.5} 14 - 18UNF 14.3
0322 54 - 93 {5.5 - 9.5} 74 {4.5}
- 16UN 17.5
24 59 - 98 {6.0 - 10.0} 78 {8.0} 18
04 27 84 - 132 {8.5 - 13.5} 103 {10.5} 22 - 16UN 20.7
05 32 128 - 186 {13.0 - 19.0} 157 {16.0} 24 1 - 14UNS 25.4
06 36 177 - 245 {18.0 - 25.0} 216 {22.0} 30 1 - 12UNF 30.3
(10) 41 177 - 245 {18.0 - 25.0} 216 {22.0} 33 (12) 46 197 - 294 {20.0 - 30.0} 245 {25.0} 36 (14) 55 246 - 343 {25.0 - 35.0} 294 {30.0} 42
9161116
1316
316
-
FOREWORD ELECTRIC WIRE CODE
00-15
ELECTRIC WIRE CODEIn the wiring diagrams, various colors and symbols are employed to indicate the thickness of wires.This wire code table will help you understand WIRING DIAGRAMS.Example: 5WB indicates a cable having a nominal number 5 and white coating with black stripe.
CLASSIFICATION BY THICKNESS
CLASSIFICATION BY COLOR AND CODE
Norminalnumber
Copper wireCable O.D.(mm)
Current rating(A) Applicable circuitNumber of
strandsDia. of strands(mm2)
Cross section(mm2)
0.85 11 0.32 0.88 2.4 12 Starting, lighting, signal etc.
2 26 0.32 2.09 3.1 20 Lighting, signal etc.
5 65 0.32 5.23 4.6 37 Charging and signal
15 84 0.45 13.36 7.0 59 Starting (Glow plug)
40 85 0.80 42.73 11.4 135 Starting
60 127 0.80 63.84 13.6 178 Starting
100 217 0.80 109.1 17.6 230 Starting
Priori-ty
Circuits
Classi-fication
Charging Ground Starting Lighting Instrument Signal Other
1 Pri-maryCode W B B R Y G L
Color White Black Black Red Yellow Green Blue
2
Auxi-liary
Code WR n BW RW YR GW LW
Color White & Red n White & Black Red & White Rellow & Red Green & White Blue & White
3Code WB n BY RB YB GR LR
Color White & Black n Black & Yellow Red & Black Yellow & Black Green & Red Blue & Yellow
4
Code WL n BR RY YG GY LY
Color White & Blue n Black & Red Red & Yellow Yellow & GreenGreen & Yellow Blue & Yellow
5Code WG n n RG YL GB LB
Color White & Green n n Red & Green Yellow & Blue Green & Black Blue & Black
6Code n n n RL YW GL n
Color n n n Red & Blue Yellow & White Green & Blue n
-
FOREWORD CONVERSION TABLE
00-16
CONVERSION TABLE
METHOD OF USING THE CONVERSION TABLEThe Conversion Table in this section is provided to enable simple conversion of figures. For details of themethod of using the Conversion Table, see the example given below.
EXAMPLE Method of using the Conversion Table to convert from millimeters to inches1. Convert 55 mm into inches.
(1) Locate the number 50 in the vertical column at the left side, take this as A, then draw a horizontal linefrom A.
(2) Locate the number 5 in the row across the top, take this as B, then draw a perpendicular line downfrom B.
(3) Take the point where the two lines cross as C. This point C gives the value when converting from mil-limeters to inches. Therefore, 55 mm = 2.165 inches.
2. Convert 550 mm into inches.(1) The number 550 does not appear in the table, so divide by 10 (move the decimal point one place to the
left) to convert it to 55 mm.(2) Carry out the same procedure as above to convert 55 mm to 2.165 inches.(3) The original value (550 mm) was divided by 10, so multiply 2.165 inches by 10 (move the decimal point
one place to the right) to return to the original value. This gives 550 mm = 21.65 inches.
Millimeters to inches
1 mm = 0.03937 in
0 1 2 3 4 5 6 7 8 9
010203040
5060708090
00.3940.7871.1811.575
1.9692.3622.7563.1503.543
0.0390.4330.8271.2201.614
2.0082.4022.7953.1893.583
0.0790.4720.8661.2601.654
2.0472.4412.8353.2283.622
0.1180.5120.9061.2991.693
2.0872.4802.8743.2683.661
0.1570.5510.9451.3391.732
2.1262.5202.9133.3073.701
0.1970.5910.9841.3781.772
2.1652.5592.9533.3463.740
0.2360.6301.0241.4171.811
2.2052.5982.9923.3863.780
0.2760.6691.0631.4571.850
2.2442.6383.0323.4253.819
0.3150.7091.1021.4961.890
2.2832.6773.0713.4653.858
0.3540.7481.1421.5361.929
2.3232.7173.1103.5043.898
B
A
C
-
FOREWORD CONVERSION TABLE
00-17
Millimeters to Inches1 mm = 0.03937 in
Kilogram to Pound1 kg = 2.2046 lb
0 1 2 3 4 5 6 7 8 9
010203040
5060708090
00.3940.7871.1811.575
1.9692.3622.7563.1503.543
0.0390.4330.8271.2201.614
2.0082.4022.7953.1893.583
0.0790.4720.8661.2601.654
2.0472.4412.8353.2283.622
0.1180.5120.9061.2991.693
2.0872.4802.8743.2683.661
0.1570.5510.9451.3391.732
2.1262.5202.9133.3073.701
0.1970.5910.9841.3781.772
2.1652.5592.9533.3463.740
0.2360.6301.0241.4171.811
2.2052.5982.9923.3863.780
0.2760.6691.0631.4571.850
2.2442.6383.0323.4253.819
0.3150.7091.1021.4961.890
2.2832.6773.0713.4653.858
0.3540.7481.1421.5361.929
2.3232.7173.1103.5043.898
0 1 2 3 4 5 6 7 8 9
010203040
5060708090
022.0544.0966.1488.18
110.23132.28154.32176.37198.42
2.2024.2546.3068.3490.39
112.44134.48156.53178.57200.62
4.4126.4648.5070.5592.59
114.64136.69158.73180.78202.83
6.6128.6650.7172.7594.80
116.85138.89160.94182.98205.03
8.8230.8651.9174.9697.00
119.05141.10163.14185.19207.24
11.0233.0755.1277.1699.21
121.25143.30165.35187.39209.44
13.23 35.27 57.32 79.37101.41
123.46145.51167.55189.60211.64
15.43 37.48 59.53 81.57103.62
125.66147.71169.76191.80213.85
17.64 39.68 61.73 83.78105.82
127.87149.91171.96194.01216.05
19.84 41.89 63.93 85.98108.03
130.07152.12174.17196.21218.26
-
FOREWORD CONVERSION TABLE
00-18
Liter to U.S. Gallon1l = 0.2642 U.S. Gal
Liter to U.K. Gallon1l = 0.21997 U.K. Gal
0 1 2 3 4 5 6 7 8 9
010203040
5060708090
0 2.642 5.283 7.92510.567
13.20915.85018.49221.13423.775
0.264 2.906 5.548 8.18910.831
13.47316.11518.75621.39824.040
0.528 3.170 5.812 8.45411.095
13.73716.37919.02021.66224.304
0.793 3.434 6.076 8.71811.359
14.00116.64319.28521.92624.568
1.057 3.698 6.340 8.98211.624
14.26516.90719.54922.19024.832
1.321 3.963 6.604 9.24611.888
14.52917.17119.81322.45525.096
1.585 4.227 6.869 9.51012.152
14.79517.43520.07722.71925.361
1.849 4.491 7.133 9.77412.416
15.05817.70020.34122.98325.625
2.113 4.755 7.39710.03912.680
15.32217.96420.60523.24725.889
2.378 5.019 7.66110.30312.944
15.58618.22820.87023.51126.153
0 1 2 3 4 5 6 7 8 9
010203040
5060708090
0 2.200 4.399 6.599 8.799
10.99813.19815.39817.59819.797
0.220 2.420 4.619 6.819 9.019
11.28113.41815.61817.81820.017
0.440 2.640 4.839 7.039 9.239
11.43813.63815.83818.03720.237
0.660 2.860 5.059 7.259 9.459
11.65813.85816.05818.25720.457
0.880 3.080 5.279 7.479 9.679
11.87814.07816.27818.47720.677
1.100 3.300 5.499 7.969 9.899
12.09814.29816.49818.69720.897
1.320 3.520 5.719 7.91910.119
12.31814.51816.71818.91721.117
1.540 3.740 5.939 8.13910.339
12.52814.73816.93819.13721.337
1.760 3.950 6.159 8.35910.559
12.75814.95817.15819.35721.557
1.980 4.179 6.379 8.57910.778
12.97815.17817.37819.57721.777
-
FOREWORD CONVERSION TABLE
00-19
kgm to ft. lb1 kgm = 7.233 ft. lb
0 1 2 3 4 5 6 7 8 9
010203040
5060708090
100110120130140
150160170180190
0 72.3144.7217.0289.3
361.7434.0506.3578.6651.0
723.3795.6868.0940.3
1012.6
1084.91157.31129.61301.91374.3
7.2 79.6151.9224.2296.6
368.9441.2513.5585.9658.2
730.5802.9875.2947.51019.9
1092.21164.51236.81309.21381.5
14.5 86.8159.1231.5303.8
376.1448.5520.8593.1665.4
737.8810.1882.4954.81027.1
1099.41171.71244.11316.41388.7
21.7 94.0166.4238.7311.0
383.4455.7528.0600.3672.7
745.0817.3889.7962.01034.3
1106.61179.01251.31323.61396.0
28.9101.3173.6245.9318.3
390.6462.9535.2607.6679.9
752.2824.6896.9969.2
1041.5
1113.91186.21258.51330.91403.2
36.2108.5180.8253.2325.5
397.8470.2542.5614.8687.1
759.5831.8904.1976.5
1048.8
1121.11193.41265.81338.11410.4
43.4115.7188.1260.4332.7
405.1477.4549.7622.0694.4
766.7839.0911.4983.7
1056.0
1128.31200.71273.01345.31417.7
50.6123.0195.3267.6340.0
412.3484.6556.9629.3701.6
773.9846.3918.6990.91063.2
1135.61207.91280.11352.61424.9
57.9130.2202.5274.9347.2
419.5491.8564.2636.5708.8
781.2853.5925.8998.21070.5
1142.81215.11287.51359.81432.1
65.1137.4209.8282.1354.4
426.8499.1571.4643.7716.1
788.4860.7933.11005.41077.7
1150.01222.41294.71367.01439.4
-
FOREWORD CONVERSION TABLE
00-20
kg/cm2 to lb/in21kg/cm2 = 14.2233 lb/in2
0 1 2 3 4 5 6 7 8 9
010203040
5060708090
100110120130140
150160170180190
200210220230240
0 142.2 284.5 426.7 568.9
711.2 853.4 995.6
11381280
14221565170718491991
21342276241825602702
28452987312932713414
14.2 156.5 298.7 440.9 583.2
725.4 867.6
101011521294
14371579172118632005
21482290243225742717
28593001314332863428
28.4 170.7 312.9 455.1 597.4
739.6 881.8
102411661309
14511593173518772020
21622304244625892731
28733015315833003442
42.7 184.9 327.1 469.4 611.6
753.8 896.1
103811811323
14651607174918922034
21762318246026032745
28873030317233143456
56.9 199.1 341.4 483.6 625.8
768.1 910.3
105311951337
14791621176419062048
21902333247526172759
29013044318633283470
71.1 213.4 355.6 497.8 640.1
782.3 924.5
106712091351
14931636177819202062
22052347248926312773
29163058320033433485
85.3 227.6 369.8 512.0 654.3
796.5 938.7
108112231365
15081650179219342077
22192361250326462788
29303072321433573499
99.6 241.8 384.0 526.3 668.5
810.7 953.0
109512371380
15221664180619492091
22332375251826602802
29443086322933713513
113.8 256.0 398.3 540.5 682.7
825.0 967.2
110912521394
15361678182119632105
22472389253226742816
29583101324333853527
128.0 270.2 412.5 554.7 696.9
839.2 981.4
112412661408
15501693183519772119
22622404254626882830
29733115325733993542
-
FOREWORD CONVERSION TABLE
00-21
TemperatureFahrenheit-Centigrade Conversion ; a simple way to convert a Fahrenheit temperature reading into a Cen-tigrade temperature reading or vice versa is to enter the accompanying table in the center or boldface col-umn of figures.These figures refer to the temperature in either Fahrenheit or Centigrade degrees.If it is desired to convert from Fahrenheit to Centigrade degrees, consider the center column as a table ofFahrenheit temperatures and read the corresponding Centigrade temperature in the column at the left.If it is desired to convert from Centigrade to Fahrenheit degrees, consider the center column as a table ofCentigrade values, and read the corresponding Fahrenheit temperature on the right.
1C = 33.8F
C F C F C F C F
40.437.234.431.728.9
28.327.827.226.726.1
25.625.024.423.923.3
22.822.221.721.120.6
20.019.418.918.317.8
17.216.716.115.615.0
14.413.913.312.812.2
4035302520
1918171615
1413121110
9 8 7 6 5
4 3 2 1 0
1 2 3 4 5
6 7 8 9 10
40.031.022.013.0 4.0
2.2 0.4 1.4 3.2 5.0
6.8 8.6 10.4 12.2 14.0
15.8 17.6 19.4 21.2 23.0
24.8 26.6 28.4 30.2 32.0
33.8 35.6 37.4 39.2 41.0
42.8 44.6 46.4 48.2 50.0
11.711.110.610.0 9.4
8.9 8.3 7.8 7.2 6.7
6.1 5.6 5.0 4.4 3.9
3.3 2.8 2.2 1.7 1.1
0.6 0
0.6 1.1 1.7
2.2 2.8 3.3 3.9 4.4
5.0 5.6 6.1 6.7 7.2
1112131415
1617181920
2122232425
2627282930
3132333435
3637383940
4142434445
51.8 53.6 55.4 57.2 59.0
60.8 62.6 64.4 66.2 68.0
69.8 71.6 73.4 75.2 77.0
78.8 80.6 82.4 84.2 86.0
87.8 89.6 91.4 93.2 95.0
96.8 98.6100.4102.2104.0
105.8107.6109.4111.2113.0
7.8 8.3 8.9 9.410.0
10.611.111.712.212.8
13.313.914.415.015.6
16.116.717.217.818.3
18.919.420.020.621.1
21.722.222.823.323.9
24.425.025.626.126.7
4647484950
5152535455
56575859 0
6162636465
6667686970
7172737475
7677787980
114.8116.6118.4120.2122.0
123.8125.6127.4129.2131.0
132.8134.6136.4138.2140.0
141.8143.6145.4147.2149.0
150.8152.6154.4156.2158.0
159.8161.6163.4165.2167.0
168.8170.6172.4174.2176.0
27.227.828.328.929.4
30.030.631.131.732.2
32.833.333.934.435.0
35.636.136.737.237.8
40.643.346.148.951.7
54.457.260.062.765.6
68.371.173.976.779.4
81 82 83 84 85
86 87 88 89 90
91 92 93 94 95
96 97 98 99100
105110115120125
130135140145150
155160165170175
117.8179.6181.4183.2185.0
186.8188.6190.4192.2194.0
195.8197.6199.4201.2203.0
204.8206.6208.4210.2212.0
221.0230.0239.0248.0257.0
266.0275.0284.0293.0302.0
311.0320.0329.0338.0347.0
-
FOREWORD UNITS
00-22
UNITS
In this manual, the measuring units are indicated with Internatinal System of units (SI).As for reference, conventionally used Gravitational System of units are indicated in parentheses { }.
Example:N {kg}Nm {kgm}MPa {kg/cm2}kPa {mmH2O}kPa {mmHg}kW/rpm {HP/rpm}g/kWh {g/HPh}
-
PC78MR-6 01-1
Specifiaction dimensions drawing ...................... 01-2Working range drawing ....................................... 01-3Specifications ...................................................... 01-4Weight table ........................................................ 01-7List of lubricants and coolant .............................. 01-9
01 GENERAL
-
01-2 PC78MR-6
GENERAL
SPECIFICATION DIMENSIONS DRAWING
Item UnitPC78MR-6
Steel shoe spec. Road liner spec.
Machine weight (with blade) kg 8,270 8,300
Bucket capacity m 0.28
Engine model KOMATSU S4D95LE-3-A Diesel engine
Rated engine output kW {HP}/rpm 40.5 {54.0}/1,850
A Overall length mm 6,200 6,230
B Overall height mm 2,730 2,750
C Overall width mm 2,330
D Shoe width mm 450
E Tail swing radius mm 1,310
F Overall length of track mm 2,840 2,900
G Distance between tumbler centers mm 2,235
Minimum ground clearance mm 360 400
Travel speed (Low/High) km/h 2.8/4.2
Continuous swing speed rpm 10.0
SPECIFICATION DIMENSIONS DRAWING
-
PC78MR-6 01-3
GENERAL
WORKING RANGE DRAWING
Working range (mm) Steel shoe spec.
A Max. digging reach 6,960
B Max. digging depth 4,160
C Max. digging height 6,570
D Max. vertical wall depth 2,900
E Max. dumping height 4,515
FMin. swing radius of work equipment 2,775
Min. swing radius at boom swinging 2,125
G Max. reach at ground level 6,750
H Max. blade lifting height 380
I Max. blade lowering depth 245
WORKING RANGE DRAWING
-
01-4 PC78MR-6
GENERAL
SPECIFICATIONS
Figures (steel shoe specification) are common to the all specifications unless otherwise specified.( ) Figures in ( ): Road liner specification
Machine model PC78MR-6
Serial Number 1001 and up
Bucket capacity m3 0.28
Machine weight kg 8,270 (8,300)
Per
form
ance W
orki
ng ra
nge
Max. digging depth mm 4,160
Max. vertical wall depth mm 2,900
Max. digging reach mm 6,960
Max. reach at ground level mm 6,750
Max. digging height mm 6,570
Max. dumping height mm 4,515
Boom swing (left side/right side) mm 580/930
Max. blade lifting height mm 380
Max. blade lowering depth mm 245
Max. digging force (Bucket) kN {kg} 61.3 {6,250}
Continuous swing speed rpm 10.0
Max. slope angle for swing deg. 16.0
Travel speed (Low/High) km/h 2.8/4.2
Gradeability deg. 35
Ground pressure kPa {kg/cm2} 37.3 {0.38}
Dim
ensi
on
Overall length (for transport) mm 6,200
Overall width mm 2,330
Overall height (for transport) mm 2,730 (2,750)
Overall height (for operation) mm 2,710 (2,750)
Ground clearance of counterweight mm 735 (780)
Min. ground clearance mm 360 (400)
Tail swing radius mm 1,310Min. swing radius of work equipment(at boom swinging) mm 2,125
Height of work equipment at min. swing radius mm 5,210 (5,230)
Overall width of track mm 2,320
Overall length track mm 2,840 (2,900)
Distance between tumbler centers mm 2,235
Track gauge mm 1,870Machine cab height mm 1,745 (1,795)
Blade width height mm 2,320 470
SPECIFICATIONS
-
PC78MR-6 01-5
GENERAL
Machine model PC78MR-6
Serial Number 1001 and up
Eng
ine
Model S4D95LE-3-A
Type 4-cycle, water-cooled, in-line, direct injection
No. of cylinders - bore stroke mm 4-95 115
Total displacement l {cc} 3.26 {3,260}
Perfo
rman
ce
Rated output kW/rpm {HP/rpm}40.5/1,850
{54.0/1,850}
Max. torque Nm/rpm {kgm/rpm}337/1,500
{24.2/1,500}Max. speed at no load rpm 2,020
Min. speed at no load rpm 1,130
Min. fuel consumption g/kWh {g/HPh} 227 {169}
Starting motor 24 V, 3.0 kw
Alternator 24 V, 25 A
Battery 12 V, 48 Ah 2 (55D26R)
Type of radiator core CF29-3
Und
erca
rria
ge Carrier roller 1 on each side
Track roller 5 on each sideTrack shoe (Steel shoe)
(Road liner)(Rubber shoe)
Assembly-type triple grouser, 39 on each sideAssembly-type road liner, 39 on each side
Unit-type rubber crawler
Hyd
raul
ic s
yste
m
Hyd
raul
ic p
ump Type No.
Variable-capacity piston pump 1Gear pump 2
Discharge l {cc} 802+60+12.7Set pressures
(Work equipment, travel)(Swing, blade)(Control)
MPa {kg/cm2}
26.5 {270}21.1 {215}3.1 {32}
Con
trol
valv
e Type No. 9-spool type 1
Control method Hydraulically assisted
Hyd
raul
icm
otor
Travel motorVariable-capacity piston motor(with brake valve, parking brake) 2
Swing motorFixed-capacity piston motor(with safety valve, pivot shaft brake) 1
Hydraulic tank Box-shaped, open
Hydraulic oil filter Tank return side
Oil cooler Air-cooled
SPECIFICATIONS
-
01-6 PC78MR-6
GENERAL
Machine model PC78MR-6
Serial Number 1001 and up
Hyd
raul
ic s
yste
m
Wor
k eq
uipm
ent c
ylin
der
Boo
m c
ylin
der
Type Reciprocating piston
Inside diameter of cylinder mm 115
Diameter of piston rod mm 65
Stroke mm 988
Max. distance between pinsmm mm 2,393
Min. distance between pinsmm mm 1,405
Arm
cyl
inde
r
Type mm Reciprocating piston
Inside diameter of cylinder mm 100
Diameter of piston rod mm 60
Stroke mm 865
Max. distance between pins mm 2,193
Min. distance between pins mm 1,328
Buc
ket c
ylin
der
Type mm Reciprocating piston
Inside diameter of cylinder mm 90
Diameter of piston rod mm 55
Stroke mm 710
Max. distance between pins mm 1,765
Min. distance between pins mm 1,055
Boo
m s
win
g cy
linde
r Type mm Reciprocating piston
Inside diameter of cylinder mm 120
Diameter of piston rod mm 60
Stroke mm 658
Max. distance between pins mm 1,687
Min. distance between pins mm 1,029
Bla
de c
ylin
der
Type mm Reciprocating piston
Inside diameter of cylinder mm 130
Diameter of piston rod mm 65
Stroke mm 130
Max. distance between pins mm 679
Min. distance between pins mm 549
SPECIFICATIONS
-
PC78MR-6 01-7
GENERAL
WEIGHT TABLEk This mass list is for reference in handling or transporting these components.
Unit: kg
Figures (steel shoe specification) are common to the all specifications unless otherwise specified.[ ] Figures in [ ]: Rubber shoe specification
Machine model PC78MR-6
Serial Number 1001 and up
Engine assembly (without water and oil) 403
Engine (without water and oil) 300
Engine mount 30
PTO 7
Hydraulic pump 66
Cooling assembly (without coolant and oil) 29
Radiator (without coolant) 6.3
Oil cooler (without oil) 5.2
Revolving frame 1,220
Operator's cab 260
Operator's seat 18
Fuel tank (without fuel) 8.3
Hydraulic tank (without hydraulic oil) 70
Control valve 62
Counterweight 950
Additional counterweight 220
Swing motor (Including brake valve) 22
Swing circle 104
Swing machinery 47
Center swivel joint 16
Track frame assembly (without track shoe) 1,067 [1,048]
Track frame 704
Idler assembly 54 x 2
Recoil spring assembly 40 x 2
Carrier roller 3.4 x 2
Track roller 13 x 10
Travel motor (with reduction gears) 81 x 2
Sprocket 19 x 2
WEIGHT TABLE
-
01-8 PC78MR-6
GENERAL
Unit: kg
Figures are common to the all specifications unless otherwise specified.
Machine model PC78MR-6
Serial Number 1001 and up
Track shoe assembly
City pad shoe (450 mm) 410 X 2
Road liner (450 mm) 450 X 2
Rubber shoe (450 mm) 385 X 2
Triple grouser (600 m) 495 X 2
Boom assembly 365
Swing bracket 234
Arm assembly 147
Bucket link assembly 56
Bucket assembly (with side cutter) 210
Blade assembly 374
Boom cylinder assembly 95
Arm cylinder assembly 72
Bucket cylinder assembly 51
Boom swing cylinder assembly 65
Blade cylinder assembly 46
WEIGHT TABLE
-
PC78MR-6 01-9
GENERAL
LIST OF LUBRICANTS AND COOLANT
*1: ASTM D975 No. 1 Unit: l
ReservoirPC78MR-6
Specified capacity Refill capacity
Engine oil pan 7.5 7.0
PTO gear case 0.4 0.4
Swing machinery case 2.0 2.0
Final drive case (each) 1.3 1.3
Hydraulic system 120 64
Fuel tank 125
Cooling system 10.5
RESERVOIRKIND OF
FLUID
AMBIENT TEMPERATURE
22 4 14 32 50 68 86 104 122F
30 20 10 0 10 20 30 40 50C
Add antifreeze
SAE 30
SAE 30
SAE 10W
*1
SAE 10W-30
SAE 10
ASTM D975 No. 2
SAE 15W-40
SAE 10W-30
SAE 15W-40
NLGI No. 2
Engine oil pan
Swing machinery caseFinal drive casePTO gear case
Hydraulic system
Fuel tank
Greasing system
Cooling system
Engine oil
Diesel fuel
Diesel fuel
Water
LIST OF LUBRICANTS AND COOLANT
-
PC78MR-6 10-1
PTO ........................................................................... 10- 2Cooling system.......................................................... 10- 3Power train system.................................................... 10- 4Swing circle ............................................................... 10- 5Swing machinery ....................................................... 10- 6Track frame and idler cushion ................................... 10- 8Idler ........................................................................... 10-10Track roller..................................................................10-11Carrier roller .............................................................. 10-12Sprocket .................................................................... 10-13Track shoe................................................................. 10-14Arrangement of hydraulic components...................... 10-19Hydraulic tank and oil filter ........................................ 10-20Center swivel joint ..................................................... 10-21Travel motor .............................................................. 10-22Work equipment cylinder ........................................... 10-30Solenoid valve ........................................................... 10-34Multi-Control Valve .................................................... 10-40Accumulator for Brake............................................... 10-41Hydraulic pump ......................................................... 10-42Control valve ............................................................. 10-56CLSS ......................................................................... 10-68Swing motor ............................................................ 10-100Work equipment and swing PPC valve ................... 10-108Travel PPC valve......................................................10-114Boom swing PPC valve, blade PPC valve ...............10-118Boom hydraulic anti-burst valve (For EU spec.) ... 10-121-1Work equipment ...................................................... 10-122Dimensions of each part of work equipment ........... 10-124Air conditioner piping (Optional) .............................. 10-128Electric control system ............................................ 10-129System components ................................................ 10-146Monitor system ........................................................ 10-154Sensors ................................................................... 10-158
10 STRUCTURE, FUNCTION ANDMAINTENANCE STANDARD
(1)
-
10-2 PC78MR-6
STRUCTURE, FUNCTION AND MAINTENANCE STANDARD
PTO
1. Drain plug2. Coupling3. Flywheel4. Pump case5. Cage6. Level plug7. Breather/Oil filler plug
PTO
-
PC78MR-6 10-3
STRUCTURE, FUNCTION AND MAINTENANCE STANDARD
COOLING SYSTEM
1. Fan guard 2. Radiator inlet hose 3. Drain valve 4. Radiator outlet hose 5. Radiator cap 6. Oil cooler 7. Radiator 8. Shroud 9. Oil cooler inlet10. Reservoir tank11. Oil cooler outlet
SPECIFICATIONS
Radiator Oil cooler
Type of core CF29-3 CF40-1
Fin pitch (mm) 4.0/2 4.5/2
Total heat dissipation area (m2) 16.53 6.15
Pressure valve cracking pressure (kPa {kg/cm})
88.314.7(0.90.15)
Vacuum valve cracking pressure (kPa {kg/cm})
4.9(0.05)
COOLING SYSTEM
-
10-4 PC78MR-6
STRUCTURE, FUNCTION AND MAINTENANCE STANDARD
POWER TRAIN SYSTEM
1. Idler2. Control valve3. Center swivel joint4. Swing motor5. Travel motor6. Control pump (for pilot control)7. Hydraulic pump (for swing and blade)8. Hydraulic pump
(For travel and work equipment)9. Engine
10. Boom RAISE stop EPC valve11. Arm IN stop EPC valve12. Left offset stop EPC vaolve13. Swing holding brake solenoid valve14. 2-stage travel speed selector solenoid valve15. PPC lock solenoid valve16. Swing machinery17. Swing circle
POWER TRAIN SYSTEM
-
PC78MR-6 10-5
STRUCTURE, FUNCTION AND MAINTENANCE STANDARD
SWING CIRCLE
Unit: mm
2. Greasing for swing circle bearing3. Greasing for swing circle pinion4. Outer race5. Inner race6. Ball7. Seal
a. Position of inner race soft zoneb. Position of outer race soft zone
Specifications
No. Item Criteria Remedy
1 Axial clearance of bearingStandard clearance Allowable clearance
Replace0.20 0.80 2.0
Reduction ratio 80/10=8.0Grease G2-LI
Quantity of grease ( ) 5.5
SWING CIRCLE
-
10-6 PC78MR-6
STRUCTURE, FUNCTION AND MAINTENANCE STANDARD
SWING MACHINERY
1. Swing pinion (Number of teeth: 10) 2. Swing machinery case 3. No. 2 planetary carrier 4. Ring gear (Number of teeth: 58) 5. No. 2 sun gear (Number of teeth: 14) 6. No. 1 planetary carrier 7. No. 1 sun gear (Number of teeth: 14) 8. Swing motor 9. Oil filler10. Level gauge11. No. 1 planetary gear (Number of teeth: 22)12. No. 2 planetary gear (Number of teeth: 22)13. Drain plug
Specification
Reduction ratio (14+58)/14X(14+58)/14 = 26.45Swing reduction ratio 26.45X8.0 = 211.59Swing speed (rpm) 10
SWING MACHINERY
-
PC78MR-6 10-7
STRUCTURE, FUNCTION AND MAINTENANCE STANDARD
Unit: mmNo. Item Criteria Remedy
1Backlash between swing motor shaft and No. 1 sun gear
Standard clearance Allowable clearance
Replace
0.03 0.11
2Backlash between No. 1 sun gear and No. 1 planetary gear
0.10 0.27 0.6
3Backlash between No. 1 planetary gear and ring gear
0.12 0.38 0.6
4Backlash between No. 1 planetary carrier and No. 2 sun gear
0.10 0.26
5Backlash between No. 2 sun gear and No. 2 planetary gear
0.10 0.27 0.6
6Backlash between No. 2 planetary gear and ring gear
0.12 0.38 0.6
7Backlash between No. 2 planetary carrier and swing pinion
0.07 0.21
8Backlash between swing pinion and swing circle
0.27 0.83 2.0
9Wear of sliding surface of swing pinion collar against oil seal
Basic dimension Allowance Allowable LimitPlating with hard chromium or replace75 0- 0.074 74.8
SWING MACHINERY
-
10-8 PC78MR-6
STRUCTURE, FUNCTION AND MAINTENANCE STANDARD
TRACK FRAME AND IDLER CUSHION
TRACK FRAME AND IDLER CUSHION
-
PC78MR-6 10-9
STRUCTURE, FUNCTION AND MAINTENANCE STANDARD
Unit: mm
4. Idler 5. Track frame 6. Carrier roller 7. Travel motor 8. Sprocket 9. Track roller10. Track shoe11. Idler cushion
11a.Support11b.Yoke11c.Recoil spring11d.Cylinder11e.Collar11f.Lubricator
12. Idler guard (Road liner specification, steel shoespecification)
13. Bracket to secure machine body for transporta-tion (for USA spec. only)
Specification
No. Item Criteria Remedy
1 Vertical width of idler guide
Basic dimension Allowable limitOverlay
Track frame 74 78Idler support 73 69
Overlay or replace
2 Lateral width of idler guide
Track frame 158 162 Overlay
Idler support 156 152 Overlay or replace
3 Recoil spring
Basic dimension Allowable limit
Replace
Free length Installed lengthInstalled
load Free lengthInstalled
loadRoad liner, steel shoe 412 323
47.4 kN{4,835 kg} 402
42.2 kN{4,305 kg}
Rubber shoe 412 283 69.2 kN{7,061 kg} 40261.6 kN
{6,284 kg}
Grease G2-LI
Quantity of grease (cc) 96 (Steel shoe, road liner)233 (Rubber shoe)
TRACK FRAME AND IDLER CUSHION
-
10-10 PC78MR-6
STRUCTURE, FUNCTION AND MAINTENANCE STANDARD
IDLER
Unit: mmNo. Item Criteria Remedy
1 Outside diameter of projected partBasic dimension Allowable limit
Overlay or replace
460 2 Outside diameter of tread 415 4073 Depth of tread 22.5 26.54 Width of projected part 43 375 Overall width 100 926 Width of tread 28.5 32
7 Clearance between idler shaft and bushing
Basic dimension
Allowance Standard clearance
Allowable clearance
Replace
Shaft Hole
44 -0.250-0.290+ 0.062
0 0.250 0.352 1.5
8 Interference between idler and bushing
Basic dimension
Allowance Standard interference
Allowable interferenceShaft Hole
50 +0.117+0.087+0.025
0 0.062 0.117
9 Side clearance of idler (Each side)Standard clearance Allowable clearance
0.190 0.395 1.5
10 Thickness of tread (at cen-ter of width of tread)Basic dimension Allowable limit
Overlay or replace13.8 9.8
Quantity of oil 60 cc (Engine oil: SAE30CD)
IDLER
-
PC78MR-6 10-11
STRUCTURE, FUNCTION AND MAINTENANCE STANDARD
TRACK ROLLER
Unit: mmNo. Item Criteria Remedy
1 Outside diameter of projected partBasic dimension Allowable limit
Overlay or replace 149
2 Outside diameter of tread 120 1133 Width of flange 43 36.64 Overall width 129 5 Width of tread 43 47.3 Overlay or replace
6 Clearance between idler shaft and bushing
Basic dimension
Allowance Standard clearance
Allowable clearance
Replace
Shaft Hole
38 -0.250-0.270+ 0.075- 0.025 0.225 0.345 1.5
7 Interference between idler and bushing
Basic dimension
Allowance Standard interference
Allowable interferenceShaft Hole
48 +0.117+0.087+0.030
0 0.057 0.117
8 Side clearance of track roller (Each side)Standard clearance Allowable clearance
0.38 0.73 1.5
9 Thickness of tread (at cen-ter of width of tread)Basic dimension Allowable limit
Overlay or replace36 32.5
Quantity of oil 210 230 cc (Gear oil: G0140)
TRACK ROLLER
-
10-12 PC78MR-6
STRUCTURE, FUNCTION AND MAINTENANCE STANDARD
CARRIER ROLLER
Unit: mmNo. Item Criteria Remedy
1 Outside diameter of treadBasic dimension Allowable limit
Overlay or replace 82 72
2 Width of tread 100
3 Interference between shaft and bearing
Basic dimension
Allowance Standard interference
Allowable interference
Replace
Shaft Hole
30 +0.009-0.0040
- 0.010-0.004
0.019
4 Interference between roller and bearing 620
- 0.013+ 0.018- 0.012
-0.031 0.012
5 Thickness of tread Basic dimension Allowable limit
Overlay or replace10 5
Quantity of oil 47 52 cc (Grease: ALVANIA EP-2)
CARRIER ROLLER
-
PC78MR-6 10-13
STRUCTURE, FUNCTION AND MAINTENANCE STANDARD
SPROCKET
Unit: mmNo. Item Criteria Remedy
1 Wear of root diameterBasic dimension Allowance Allowable limit
Overlay or replace
433.004 +1.0-2.0 421
2 Wear of tip diameter 483.7 2.0 4723 Wear of dip width 28 - 23
4 Wear of root width 38 +0.5-2.5 33
5 Thickness of root 84.002 +0.475-1.150 78
SPROCKET
-
10-14 PC78MR-6
STRUCTURE, FUNCTION AND MAINTENANCE STANDARD
TRACK SHOECITY PAD SHOE, ROAD LINER, AND TRIPLE SHOE
*1. City pad shoeTriple shoe (OPT)
*2. Road liner (OPT)
a Part P is the link on the press fitting side of bushing.
TRACK SHOE
-
PC78MR-6 10-15
STRUCTURE, FUNCTION AND MAINTENANCE STANDARD
Unit: mm
Items marked with * are for the dry track.
No. Item Criteria Remedy
1 Link pitchBasic dimension Allowable limit
Reverse or replace154.25 157.252 Outside diameter of bushing 41.2 37.23 Height of link 74 70
Repair or replace4 Thickness of link (Press fit-ting part of bushing) 20 16
5Shoe bolt pitch
89Replace6 73
7 57
8
Link
Inside width 45
Repair or replace9 Overall width 30
10 Width of tread 26.3
11 Projection of pin 3
Adjust or replace
12 Projection of regular bush-ing 3.15
13 Overall length of pin 131
14 Overall length of bushing (Master bushing) 74.6
15 Thickness of bushingBasic dimension Allowable limit
8.4 4.416 Thickness of spacer 17
Press fitting pressure
Bushing 19.6 98.1 kN {2 10 ton}
18 Regular pin 49.0 117.7 kN {5 12 ton}
*19 Master pin 39.2 78.5 kN {4 8 ton}
TRACK SHOE
-
10-16 PC78MR-6
STRUCTURE, FUNCTION AND MAINTENANCE STANDARD
Unit: mm
Items marked with * are for the dry track.
No. Item Criteria Remedy
20Shoe bolt
a. Regular link
Tightening torque (Nm {kgm}) Retightening angle (deg.)
Retighten
City pad Triple
117.7 19.6{12 2} 90 10
Road liner 117.7 19.6{12 2}
60 10(Torque after retightening)
Min. 343 Nm {35 kgm}
b. Master linkTightening
torqueRetightening angle (deg.) Lower limit torque
Number of shoes (Each side) 39
21 Number of shoes(Each side)
Basic dimen-sion
Allowance Standard interference
Adjust or replace
Shaft Hole
41 +0.214+0.174+0.062
0 0.112 0.214
22 Interference between regular pin and link 24+0.150
0-0.198-0.250 0.198 0.400
23 Clearance between regular pin and bushing
Basic dimen-sion
Allowance Standard clearanceShaft Hole
24 +0.1500+0.830+0.330 0.180 0.830
*24 Interference between master pin and link
Basic dimen-sion
Allowance Standard interferenceShaft Hole
24 +0.020-0.020-0.198-0.250 0.178 0.270
*25 Clearance between master pin and bushing
Basic dimen-sion
Allowance Standard clearanceShaft Hole
24 -0.150-0.250+0.630+0.230 0.380 0.880
26 Height of grouserBasic dimension Allowable limit
ReplaceRoad liner 42 19
TRACK SHOE
-
PC78MR-6 10-17
STRUCTURE, FUNCTION AND MAINTENANCE STANDARD
TRIPLE SHOE AND CITY PAD SHOE
Unit: mmNo. Item Criteria Remedy
1 Height of grouserBasic dimension Allowable limit
Overlay or replace
20 122 Overall height of shoe 26 183 Thickness of plate 64
Length of base of grouser20
5 166
Length of upper side of grouser14
7 108 12
TRACK SHOE
-
10-18 PC78MR-6
STRUCTURE, FUNCTION AND MAINTENANCE STANDARD
RUBBER SHOE (OPTIONAL)
Unit: mmNo. Item Criteria Remedy
1 Wear of lug heightBasic dimension Allowable limit
Replace30 5
2 Wear of roller guide 42 58
3 Wear of meshing part of sprocketBasic dimension Allowance Allowable limit
22.5 0.5 27
TRACK SHOE
-
PC78MR-6 10-19
STRUCTURE, FUNCTION AND MAINTENANCE STANDARD
ARRANGEMENT OF HYDRAULIC COMPONENTS
1. Bucket cylinder 2. Arm cylinder 3. Boom cylinder 4. Boom swing cylinder 5. Hydraulic tank 6. Control valve 7. Swing motor 8. Hydraulic pump 9. Oil cooler10. Travel motor11. Left work equipment PPC valve
12. Blade PPC valve13. Right work equipment PPC valve14. Center swivel joint15. Service PPC valve (Machine to which attach-
ments can be installed)16. Travel PPC valve17. 6-spool solenoid valve18. Boom swing PPC valve19. Blade cylinder20. Boom hydraulic anti-burst valve (For EU spec.)
(1)
ARRANGEMENT OF HYDRAULIC COMPONENTS
-
10-20 PC78MR-6
STRUCTURE, FUNCTION AND MAINTENANCE STANDARD
HYDRAULIC TANK AND OIL FILTER
1. Hydraulic tank2. Sight gauge3. Strainer4. Drain plug5. Filter6. Bypass valve7. Oil filler cap
Specification
Tank capacity ( ) 80
Quantity of oil in tank ( ) 64
Bypass valve set pressure (kPa {kg/cm})
0.15 0.03{1.53 0.3}
Pressure valve cracking pressure (kPa {kg/cm})
38 15{0.39 0.15}
Vacuum valve cracking pressure (kPa {kg/cm})
0 5{0 0.05}
HYDRAULIC TANK AND OIL FILTER
-
PC78MR-6 10-21
STRUCTURE, FUNCTION AND MAINTENANCE STANDARD
CENTER SWIVEL JOINT
1. Cover2. Rotor
3. Slipper seal4. Shaft
Unit: mm
A1: From right travel control valve A2: To right travel motorB1: From right travel control valve B2: To right travel motorC1: From left travel control valve C2: To left travel motorD1: From left travel control valve D2: To left travel motorE1: From blade control valve E2: To blade cylinder bottomF1: From blade control valve F2: To blade cylinder headG1: From 2-stage travel speed selector solenoid valve G2: To 2-stage travel speed selector solenoid valve
DR1: To tank DR2: From travel motor drain port
No. Item Criteria Remedy
5Clearance between rotor and shaft
Basic dimension Standard clearance Allowable clearanceReplace
70 0.056 0.105 0.111
CENTER SWIVEL JOINT
-
10-22 PC78MR-6
STRUCTURE, FUNCTION AND MAINTENANCE STANDARD
TRAVEL MOTOR
A. From travel control valveB. From travel control valveD. To tankP. From 2-stage travel speed selector solenoid
valve
TRAVEL MOTOR
-
PC78MR-6 10-23
STRUCTURE, FUNCTION AND MAINTENANCE STANDARD
1. Check valve2. Counterbalance valve3. Valve plate4. Cylinder5. Brake piston6. Plate7. Disc8. Piston9. Swash plate10. Regulator piston11. RV gear12. RV gear13. Case
14. Shaft15. Drive gear16. Cover17. Crankshaft18. Drain plug19. Driven gear20. Pivot21. Spindle22. Floating seal23. End cover24. Regulator valve25. Check valve
TRAVEL MOTOR
-
10-24 PC78MR-6
STRUCTURE, FUNCTION AND MAINTENANCE STANDARD
Specification
Outline
1. Reduction gearsThe reduction gears consists of spur gear unit(1a) and differential gear unit (1b) which usespericycloid gears and converts the high speedrevolution of the hydraulic motor into low-speedand high-torque revolution.
2. Hydraulic motorThe hydraulic motor is a swash plate-type axialpiston motor, which converts the power of thehydraulic oil sent from the hydraulic pump intorevolution.
3. Brake valveThe brake valve consists of various valves andhas functions of stopping the hydraulic motorsmoothly, preventing the hydraulic motor fromrunning away, and preventing generation ofabnormally high pressure when the hydraulicmotor is stopped suddenly.
4. 2-stage travel speed changeover mechanismThe 2-stage travel speed changing mechanismconsists of a changeover valve and a piston,which change the displacement of the hydraulicmotor to either of 2 stages.
5. Parking brakeThe parking brake is a friction plate brake, whichis built as a part of the hydraulic motor.
Model GM09VN-E
Theoretical displacement (cm/rev)
Hi 24.1Lo 36.3
Rated speedHi 3,211Lo 2,154
Brake releasing pressure (MPa {kg/cm})
0.47{4.8}
Speed changeover pressure(MPa {kg/cm})
2.94{30}
Reduction ratio 66.5
TRAVEL MOTOR
-
PC78MR-6 10-25
STRUCTURE, FUNCTION AND MAINTENANCE STANDARD
OPERATION
Operation of motor
At low speed (With swash plate angle at maximum)
1. 2-stage travel speed selector solenoid valve 2. Regulator valve 3. Spring 4. Check valve 5. End cover 6. Regulator piston 7. Swash plate 8. Pump merge-divider valve 9. Travel control valve10. Brake valve
Since 2-stage travel speed selector solenoidvalve (1) is de-energized, the hydraulic oil fromthe control pump does not flow into port Pi.
Accordingly, regulator valve (2) is pressed to theleft by spring (3).
Under this condition, the main hydraulic oil fromthe control valve pushes check valve (4) andflows into end cover (5) and then is shut off byregulator valve (2).
The hydraulic oil in control chamber (a) flowsthrough passage (b) of regulator valve (2) intothe motor case.
As a result, swash plate (7) is pushed toward themaximum swash plate angle by the main hydrau-lic oil in chamber (P) of the cylinder and themotor capacity is increased to the maximum andthe travel speed lowers.
TRAVEL MOTOR
-
10-26 PC78MR-6
STRUCTURE, FUNCTION AND MAINTENANCE STANDARD
At high speed (With swash plate angle at minimum)
1. 2-stage travel speed selector solenoid valve 2. Regulator valve 3. Spring 4. Check valve 5. End cover 6. Regulator piston 7. Swash plate 8. Pump merge-divider valve 9. Travel control valve10. Brake valve
If 2-stage travel speed selector solenoid valve(1) is energized, the pilot pressure from the con-trol pump flows into port Pi and pushes regulatorvalve (2) to the right.
Accordingly, the main hydraulic oil from the con-trol valve flows through passage (c) of regulatorvalve (2) into control chamber (a) and pushesregulator piston (6) to the left.
As a result, swash plate (7) is pushed toward theminimum swash plate angle and the motorcapacity is decreased to the minimum and thetravel speed rises.
TRAVEL MOTOR
-
PC78MR-6 10-27
STRUCTURE, FUNCTION AND MAINTENANCE STANDARD
Operation of brake valve The brake valve consists of check valves (1a)
and (1b) and counterbalance valve spool (2) asshown in the following figure.
Function When the machine travels downhill, its speed
may become higher than the motor speedbecause of its momentum. If the engine speed islow at this time, the motor runs idle and themachine runs away, and this situation is verydangerous. The brake valve prevents this phe-nomenon and limits the travel speed accordingto the engine speed (pump discharge).
Operation when oil is supplied If the travel lever is operated, the hydraulic oil
from the control valve flows in port PA, pushesvalve (1a) open, and flows through motor inputport MA to motor outlet port MB.At the same time, the hydraulic oil also flowsthrough orifice c of spool (2) to chamber D. If itspressure becomes higher than the pressure ofspring (3), spool (2) is pushed to the left. As aresult, port MB is connected to port PB and themotor outlet side opens and the motor starts rev-olution.Since port PA is connected to port E, too, thehydraulic oil operates parking brake piston (4) torelease the parking brake force.
TRAVEL MOTOR
-
10-28 PC78MR-6
STRUCTURE, FUNCTION AND MAINTENANCE STANDARD
Operation when oil is shut off If the control lever is returned to neutral, the
hydraulic oil from the control valve is shut off andspool (2) is returned to the right by the reactionforce of spring (3).At this time, the oil flows through orifice (c) ofchamber D into port PA and back pressure isgenerated by the throttle effect of orifice (c). Thisback pressure controls the speed of spool (2)returning to the right.
Even after the hydraulic oil in port PA is shut off,the motor continues revolution by inertia.
At this time, the returning oil is reduced graduallyaccording to the changing speed and shape ofspool (2) to stop the motor smoothly.
The motor continues revolution by inertia andcan cause cavitation. Since valve (1a) is oper-ated by very slight negative pressure, however, itopens ports PA and MA to prevent cavitation.
Operation of brake during downhill travel If the machine starts running away while travel-
ing downhill, the motor revolves idle and thepressure on the motor inlets side lowers, thenthe pressure in chamber D also lowers throughorifice (c).If the pressure in chamber D lowers below thepressure of spring (3), spool (2) is pushed backto the right.At this time, the oil in chamber G flows throughorifice (f) into port PB. The throttle effect of ori-fice (f) generates back pressure, and spool (2)returns to the right to control the returning speedof spool (2). Port MB on the outlet side is nar-rowed.As a result, the pressure on the outlet side risesand revolving resistance is generated in themotor to prevent the machine from running away.To put it concretely, spool (2) moves to a positionat which the machine weight and the pressure onthe inlet side are balanced with the pressure atport MB on the outlet side to narrow the outletcircuit. Consequently, the speed is controlledaccording to the pump discharge.
TRAVEL MOTOR
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PC78MR-6 10-29
STRUCTURE, FUNCTION AND MAINTENANCE STANDARD
Operation of parking brake
When travel lever is operated If the travel lever is operated, the hydraulic oil
from the pump moves spool (1) to the left andflows through port E into chamber A of brake pis-ton (2), then pushes brake piston (2) to the left.
As a result, the pressing force of spring (5) givento plate (3) and disc (4) is lost, then plate (3) anddisc (4) are separated and the brake force isreleased.
When travel lever is set to neutral position If the travel lever is set to the neutral position, the
hydraulic oil from the pump is shut off.The hydraulic oil in chamber (a) of brake piston(2) is drained into the case and piston (2) ispushed to the right by spring (5).As a result, plate (3) and disc (4) are pressedand the braking force is applied.
TRAVEL MOTOR
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10-30 PC78MR-6
STRUCTURE, FUNCTION AND MAINTENANCE STANDARD
WORK EQUIPMENT CYLINDERBoom cylinder
Arm cylinder
Bucket cylinder
WORK EQUIPMENT CYLINDER
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PC78MR-6 10-31
STRUCTURE, FUNCTION AND MAINTENANCE STANDARD
Boom swing cylinder
Blade cylinder
WORK EQUIPMENT CYLINDER
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10-32 PC78MR-6
STRUCTURE, FUNCTION AND MAINTENANCE STANDARD
Unit: mmNo. Item Criteria Remedy
1 Clearance between piston rod and bushing
Cylinder name
Basic dimension
Allowance Standard clearance
Allowable clearance
Replace bushing
Shaft Hole
Boom 65 -0.030-0.104+0.250+0.055
0.085 0.354 0.654
Arm 60 -0.030-0.104+0.163+0.006
0.036 0.267 0.567
Bucket 55 -0.030-0.104+0.163+0.006
0.036 0.267 0.567
Boom swing 60
-0.030-0.104
+0.163+0.006
0.036 0.267 0.567
Blade 65 -0.030-0.104+0.250+0.055
0.085 0.354 0.654
2Clearance between piston rod support shaft and bushing
Boom 60 -0.030-0.100+0.174+0.100
0.130 0.274 1.0
Replace pin and
bushing
Arm 60 -0.030-0.100+0.174+0.100
0.130 0.274 1.0
Bucket 60 -0.030-0.100+0.174+0.100
0.130 0.274 1.0
Boom swing 65
-0.030-0.100
+0.174+0.100
0.130 0.274 1.0
Blade 70 -0.030-0.104+0.174+0.100
0.130 0.278 1.0
3Clearance between
cylinder bottom support shaft and bushing
Boom 65 -0.030-0.100+0.174+0.100
0.130 0.274 1.0
Arm 55 -0.030-0.100+0.174+0.100
0.130 0.274 1.0
Bucket 50 -0.030-0.100+0.142+0.080
0.110 0.242 1.0
Boom swing 65
-0.030-0.076
+0.174+0.100
0.130 0.250 1.0
Blade 70 -0.030-0.104+0.174+0.100
0.130 0.278 1.0
4 Tightening torque of cylinder head
Boom 961 96.1 Nm {98 9.8 kgm}
Retighten
Arm 785 78.5 Nm {80 8.0 kgm}
Bucket
Procedure 1) Tighten to 1.18 1.37 kNm {120 140 kgm}.2) Loosen to 0 Nm {0 kgm}.3) Tighten to 0.39 kNm {40 kgm}.4) Control tightening of cylinder head by
turning angle (Turning distance: 3.5 4.5 mm).Boom swing 981 98.1 Nm {100 10.0 kgm}
Blade 1.030 103.0 Nm {105 10.5 kgm}
5 Tightening torque of cylinder piston
Boom 3.33 0.33 kNm {340 34.0 kgm} (2 Width across flats: 70 mm)Arm 2.65 0.26 kNm {270 27.0 kgm} (2 Width across flats: 65 mm)
Bucket 2.16 0.22 kNm {220 22.0 kgm} (2 Width across flats: 60 mm)Boom swing 2.6 0.26 kNm {265 26.0 kgm} (2 Width across flats: 70 mm)
Blade 3.14 0.31 kNm {320 32.0 kgm} (2 Width across flats: 75 mm)
WORK EQUIPMENT CYLINDER
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10-34 PC78MR-6
STRUCTURE, FUNCTION AND MAINTENANCE STANDARD
SOLENOID VALVE
Serial No.: 1001 1094
SOLENOID VALVE
(1)
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PC78MR-6 10-35
STRUCTURE, FUNCTION AND MAINTENANCE STANDARD
A: From control pumpA4: PlugA5: From left work equipment PPC valve "ARM IN"A6: From right work equipment PPC valve "BOOM RAISE"B1: To PPC valveB2: To 2-stage travel speed selection valveB3: To swing holding brakeB4: PlugB5: To control valve "ARM IN"B6: To control valve "BOOM RAISE"
T: To hydraulic tank
1. Left boom swing stop EPC valve2. Right boom swing stop EPC valve3. Not used4. Swing holding brake solenoid valve5. 2-stage travel speed selector solenoid valve6. PPC lock solenoid valve
Solenoid valve7. Coil (ON-OFF type)8. Push pin9. Valve spool
10. Return spring11. Valve body
EPC valve12. Return spring13. Guide14. Valve spool15. Push pin16. Coil (Proportional)
Check valve17. Plug18. Spring19. Ball
Control relief valve20. Adjustment screw21. Locknut22. Guide23. Return spring24. Valve spool
SOLENOID VALVE
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10-35-1 PC78MR-6
STRUCTURE, FUNCTION AND MAINTENANCE STANDARD
Serial No.: 1095 and up
SOLENOID VALVE
(1)
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PC78MR-6 10-35-2
STRUCTURE, FUNCTION AND MAINTENANCE STANDARD
A: From control pumpA5: From left work equipment PPC valve "ARM IN"A6: From right work equipment PPC valve "BOOM RAISE"B1: To PPC valveB2: To 2-stage travel speed selection valveB3: To swing holding brakeB4: PlugB5: To control valve "ARM IN"B6: To control valve "BOOM RAISE"
T: To hydraulic tank
1. Left boom swing stop EPC valve2. Right boom swing stop EPC valve3. Swing holding brake solenoid valve4. 2-stage travel speed selector solenoid valve5. PPC lock solenoid valve
Solenoid valve6. Coil (ON-OFF type)7. Push pin8. Valve spool9. Return spring
10. Valve body
EPC valve11. Return spring12. Guide13. Valve spool14. Push pin15. Coil (Proportional)
Check valve16. Plug17. Spring18. Ball
Control relief valve19. Adjustment screw20. Locknut21. Guide22. Return spring23. Valve spool
(1)
SOLENOID VALVE
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10-36 PC78MR-6
STRUCTURE, FUNCTION AND MAINTENANCE STANDARD
PPC LOCK SOLENOID VALVE2-STAGE TRAVEL SPEED SELECTOR SOLENOID VALVESWING HOLDING BRAKE SOLENOID VALVE
Operation
When solenoid is de-energized (circuit is broken) While a signal current does not flow from the
PPC hydraulic lock switch or travel speed boostpedal, solenoid (1) is de-energized.Accordingly, spool (2) is pressed up by spring(3).
Under this condition, port A is closed and thepilot hydraulic oil does not flow into the actuator.At the same time, the oil from the actuator isdrained through ports B and T into the tank.
When solenoid is energized (circuit is made) If a signal current flows from the PPC hydraulic
lock switch or travel speed boost pedal to sole-noid (1), solenoid (1) is energized.
Accordingly, spool (2) is pushed down by pushpin (4).
Under this condition, the pilot hydraulic oil flowsthrough port A, spool (2), and port B into theactuator.At the same time, port T is closed and the oildoes not flow into the tank.
SOLENOID VALVE
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PC78MR-6 10-37
STRUCTURE, FUNCTION AND MAINTENANCE STANDARD
LEFT BOOM SWING STOP EPC VALVERIGHT BOOM SWING STOP EPC VALVE
Operation
When signal current is maximum (When coil isenergized and circuit pressure is maximum) If the signal current flows from the controller into
coil (1), coil (1) is energized.At this time, the thrust of coil (1) is maximum.
As a result, spool (2) is pushed down by push pin(3).
Accordingly, all the pressurized oil from the PPCvalve flows through port A, spool (2), and port Bto the control valve.At this time, port T is closed and any oil does notflow in the tank.
When signal current is reduced (When coil isenergized and circuit pressure is low) If the signal current flowing from the controller
into coil (1) is reduced, coil (1) is still energizedbut its thrust is lowered in proportion to the signalcurrent.
As a result, push pin (3) pushes down spool (2)and the pressurized oil from port A flows to portB.
If the pressure in port B rises and the forceapplied to face "a" of spool (2) becomes largerthan the thrust of coil (1), spool (2) is pushed upand port A is disconnected from port B and con-nected to port T.
Accordingly, spool (2) moves up and down sothat the thrust of coil (1) will be balanced with thepressure in port B.
As a result, the circuit pressure between thePPC valve and control valve is controlled in pro-portion to the signal current.
SOLENOID VALVE
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10-38 PC78MR-6
STRUCTURE, FUNCTION AND MAINTENANCE STANDARD
When signal current is 0 (When coil is de-ener-gized and circuit cut out) If the signal current flowing from the controller
into coil (1) becomes 0, coil (1) is deenergized. As a result, spool (2) is pressed up by return
spring (4). Accordingly, port A is closed and the pressurized
oil from the PPC valve does not flow into thecontrol valve.At this time, the oil from the control valve isdrained through ports B and T into the tank.
Signal current is 0 o increased o maximum The valve operates in the order of 3, 2, and 1
explained above.
SOLENOID VALVE
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PC78MR-6 10-39
STRUCTURE, FUNCTION AND MAINTENANCE STANDARD
Control relief valve
If the pressure of the hydraulic oil from the con-trol pump rises, the oil in port A pushes spool (1).The reaction force of spool (1) compressesspring (2) and moves spool (1) to the right toopen ports A and T to relieve the circuit. Set pressure: 3.1 MPa {32 kg/cm}
SOLENOID VALVE
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10-40 PC78MR-6
STRUCTURE, FUNCTION AND MAINTENANCE STANDARD
MULTI-CONTROL VALVE(OPTIONAL)
(1) JIS Pattern (2) Backhoe Pattern* Operation pattern selection drawing (Port names correspond to symbols in drawing)
MULTI-CONTROL VALVE
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PC78MR-6 10-41
STRUCTURE, FUNCTION AND MAINTENANCE STANDARD
ACCUMULATOR FOR BRAKE(If equipped)
1. Cap2. Core3. Guard rubber4. Lid5. Plug6. Shell
SpecificationType of gas Nitrogen Gas
Gas volume ( ) 0.48Sealed gas pressure
(MPa {kg/cm}) 0.1 {1} (at 80 C)Max. actuating pressure
(MPa {kg/cm}) 6.86 {70}
(1)
ACCUMULATOR FOR BRAKE
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10-42 PC78MR-6
STRUCTURE, FUNCTION AND MAINTENANCE STANDARD
HYDRAULIC PUMP
Model: LPD45 + 45
P1 : Pump dischargeP2 : Pump dischargeP4 : Pilot pump dischargePD : DrainPM : PC mode changeover pressure pickup portP1T : Travel deviation adjustment orificeP2T : Travel deviation adjustment orifice
PD2 : Pump drain (plug)PDA : Air bleederPEN : Control pressure pickup portPLS : LS pressure input (From control valve)PPT : PTO oil fillerPS1 : Main pump suctionPEPC : EPC main pressure pickup portPPLS : Pump pressure input (From control valve)