Property of American Airlines Maintenance · 2018-12-03 · Figure 3. CHECK. I. SERVICING B....

Prope

rty o

f Am

erica

n Airli

nes

ceastin

Typewritten Text

Maintenance

ceastin

Typewritten Text

Chapter 2-Contents Aug, 1997 p. 2

Maintenance

SECTION PAGE

E. MAIN POWER ("IGNITION") SWITCH REMOVAL ....................................................................... 2

F. MAIN POWER ("IGNITION") SWITCH INSTALLATION ............................................................... 2

G. MASTER CYLINDER REMOVAL .................................................................................................. 3

H. MASTER CYLINDER INSTALLATION ........................................................................................... 3

I. STEER VALVE REMOVAL.......................................................................................................... ... 3

J. STEER VALVE INSTALLATION ..................................................................................................... 4

K. TIRES AND WHEELS ................................................................................................................... 4

M. ACCELERATOR PEDAL INSTALLATION: .................................................................................... 6

N. HYDRAULIC STEERING PUMP REMOVAL ................................................................................. 6

O. HYDRAULIC STEERING PUMP INSTALLATION ......................................................................... 7

P. BRAKE BOOSTER PUMP REMOVAL .......................................................................................... 8

Q. BRAKE BOOSTER PUMP INSTALLATION................................................................................... 8

R. REPLACE DRIVE MOTOR BRUSHES ......................................................................................... 9

S. DRIVE MOTOR(S) REMOVAL .................................................................................................... 10

T. DRIVE MOTOR(S) INSTALLATION............................................................................................. 11

U. CONTACTOR TIPS REMOVAL/REPLACEMENT ....................................................................... 11

V. BATTERY REMOVAL/REPLACEMENT: ...................................................................................... 13

W. SERVICE BRAKES REMOVAL/INSTALLATION ......................................................................... 13

X. PLANETARY REDUCTION HUBS REMOVAL ............................................................................ 14

Y. PLANETARY REDUCTION HUBS INSTALLATION .................................................................... 14

IV. ADJUSTMENTS................................................................................................................. ..................... 1

A. PARK BRAKE ................................................................................................................................ 1

B. SERVICE BRAKE ADJUSTMENT ................................................................................................. 1

Prope

rty o

f Am

erica

n Airli

nes


SECTION PAGE

C. VERTICAL HEADLIGHT ADJUSTMENT....................................................................................... 1

D. FRONT SPRING PRELOAD ADJUSTMENT ................................................................................ 2

E. BLEED REAR BOOSTED BRAKES (CONT) ................................................................................ 4

V. INSTRUCTIONS FOR JACKING AND POSITIONING VEHICLE ......................................................... 1

A. SAFETY PREREQUISITES........................................................................................................... 1

B. PROCEDURE ................................................................................................................................ 1

Prope

rty o

f Am

erica

n Airli

nes


(This Page Intentionally Left Blank)

Prope

rty o

f Am

erica

n Airli

nes

Chapter 2: Maintenance Sept. 1995 Section 2-1 p. 1

I. SERVICING

A complete preventive maintenance checklist is included in Chapter 5 of this manual (Appendices).See section 5-1.

A. GENERAL PREPARATIONS FOR USE:

1. Battery

Assuming a minimum 80% charge, the duration of usable charge of the M3 battery willvary from several hours to perhaps a day or more, depending on many factors. Variablesthat affect length of usable charge include the percentage of initial day's charge, intensityof use, size and condition of battery, weight of towed loads as well as environmentalfactors such as ambient temperature. The battery should be fully charged before the unitis put into service on a daily basis. For a complete discussion on battery charging cyclesand electrolyte maintenance, see chapter 1-5.

(a) Check the battery fluid level. Top up with distilled or approved drinking water, asnecessary.

(b) Connect the battery cables, if disconnected, positive first.

2. Brake System

(a) Check master cylinder fluid level.

Should the brake system require fluid, the master cylinder is located behind theconsole panel to the right of the steering wheel. Master cylinder reservoir should betopped off with a high quality brake fluid, DOT 3 or better.

The second brake fluid reservoir is located in the right service compartment abovethe hydraulic pump (See Figure 1). The brake booster pump that provides brakingpower to the rear wheels.

If low, check for leaks in brake lines.

Figure 1

Prope

rty o

f Am

erica

n Airli

nes


I. SERVICING

A. GENERAL PREPARATIONS FOR USE:

2. Brake System (cont)

(b) Service brakes should be tested for pedal firmness and braking effectiveness.

(c) Check park brake. With the main switch in the off position, the park brake shouldhold the unit in place on a 10% grade.

IMPORTANT: Drive train has no "park" position and must rely on park brake toprevent vehicle from rolling. Always make sure park brake is properlyadjusted before putting vehicle into service.

Adjust park brake cable tension by rotating caphandle on park brake lever.

3. Check Tire Inflation.

4. Check hydraulic fluid level.(Refer to lubrication section, ch. 2-1B)

Figure 1: Brake System LayoutPro

perty

of A

mer

ican

Airline

s


B. PREVENTIVE MAINTENANCE SCHEDULE (SEE ALSO: PREVENTATIVE MAINTENANCECHART IN APPENDICES CHAPTER)

THE TRACTOR SHOULD BE MAINTAINED IN ACCORDANCE WITH THE FOLLOWINGSCHEDULES:

1. Daily; Check:

(a) That all controls are in good working order. Report a faulty TUG control and do notuse until repaired.

(b) Battery charge level.

(c) Hydraulic fluid level.

(d) Battery electrolyte level

(e) The pressure of the pneumatic tires:

Drive Wheels 60 psiSteer Wheels 40 psi

WARNING: Do not change pneumatic tire for cushion tire or vice versawithout first consulting TUG Manufacturing Corporation. Tires of a differenttype or make, tread or material can reduce the load capacity or affect safety.

(f) The tire treads for damage. Remove any stone, etc.

(g) The operation of the headlights and if aimed correctly.

(h) The operation of backup, tail, stop and turn signal lights (if so equipped).

(i) The operation of the cab marker lights, the heater, the wiper and cab light, ifequipped.

(j) The horn.

2. Weekly or 50 Hour Check:

(a) Lug Nut tightness: The wheel lug nuts are tightened to 125 ft. - lbs.

WARNING: Lug nuts must be retightened to 125 ft. - lbs. after any change of awheel and anytime the lug nuts have been loosened for any reason, and at theintervals specified in this Preventive Maintenance Section.

(b) The level of the brake fluid in the master cylinder & brake booster. If low, top up asnecessary.

Prope

rty o

f Am

erica

n Airli

nes


Figure 3

CHECK

I. SERVICING

B. PREVENTIVE MAINTENANCE SCHEDULE (CONT)

3. Monthly or 200 Hour Check:

(a) The Parking Brake

With the parking brake handle in ‘lock’ position, the tractor should not move on an 10or less percent grade. If the tractor does not move, no adjustment is necessary, butif the tractor rolls, then adjustment is advised. Follow the recommended adjustmentinstructions in this Section.

(b) Power steering fluid.

(c) Planetary Reduction Hub fluid level.

(d) The adjusting slides beneath the operator’s seat.

(e) The service brake pedal pivot.

(f) The parking brake linkage.

(g) The throttle linkage.

(h) The steering axle & king pins adjustment.

(i) The sliding pins on therear brake calipers.

(j) All grease fittings.

(k) Console and batterycover latches andhinges.

(l) Cab door handles (ifequipped).

4. Two (2) Months or 400 Hours;Check:

Inspect Front wheel bearings;clean and repack.

5. Yearly or 2400 Hours

(a) Drain, flush and refill the hydraulic brake system, and bleed the brake system.

Prope

rty o

f Am

erica

n Airli

nes


(b) Drain, flush and refill the hydraulicsteering system.

(c) Drain & refill planetary drive hubs.(See Figure 3 and Chapter 5 Supplement)

6. Lubricant Chart

(a) Schematic

ITEM # COMPONENT/SYSTEM

1 STEER CYLINDER ENDS

2 KING PINS (TOP)

3 TIE ROD ENDS

4 KING PINS (BOTTOM)

5 WHEEL BEARINGS

6 PLANETARY REDUCTION HUBS

7 HYDRAULIC PUMP

8 BRAKE BOOSTER PUMP

(b) Alphabetical Table

Component/System Lubricant Type or Specification

Adjusting Slides, Seat, Operator’s Multipurpose lithium-based greaseAxle Hubs, Front Multipurpose lithium-based greaseBrake Calipers. Rear Silicon Base GreaseCab Door Handles Multipurpose lithium-based greaseHydraulic Brake System Brake Fluid, DOT 3, Extra Heavy DutyPower Steering Fluid Transmission Fluid; Dexron Type IISteering King Pins Multipurpose lithium-based grease

Figure 4

Prope

rty o

f Am

erica

n Airli

nes


B. PREVENTIVE MAINTENANCE SCHEDULE

6. Lubricant Tables (cont.)

(c) Lubricant to Component/System Table:

Hydraulic Fluid, DOT 3, Extra Heavy Duty: Hydraulic Brake System

Multipurpose Lithium based Grease: Adjusting Slides, Seat, Operator’sAxle Hubs, FrontBrake Pedal PivotCab Door HandlesDrive Shaft JointsHood Latch and HingesParking Brake LinkageSteer King PinsRear Brake Calipers

(d) Lubricant to (Commercially Available) Product Table

Hydraulic Fluid, DOT 3, Extra Heavy Duty

-Lockheed Super 105 Hydraulic Fluid

Multipurpose Lithium-based Grease

-Texaco Marfak Multipurpose 2

Silicon Base Grease

-Ford Part No. D7AZ-19A-331-A

Planetary Reduction Hub Fluid

-Amzoil Lubricant

Prope

rty o

f Am

erica

n Airli

nes

Chapter 2: Maintenance Mar, 1996 Section 2-2 p. 1

II. Troubleshooting

The M3 is an electric vehicle and depends on sound electrical connections for all its power.Subesquently, a higher emphasis should be placed on checking for and maintaining clean, corrosion-free electrical connections. Many of the troubleshooting procedures listed in the following pagesindicate possible connection or contact problems that might prevent the proper flow of electricity fromone point to the next. IN ANY TROUBLESHOOTING PROCEDURE, ALWAYS LOOK FOR APPRO-PRIATE ELECTRICAL CONNECTIONS BEFORE ATTEMPTING TO REMOVE, REPLACE ORTROUBLESHOOT COMPONENTS.

WARNING! WHEN TESTING AN ELECTRIC VEHICLE, JACK THE DRIVE WHEELS OFF THEGROUND AND SECURE IN THIS POSITION WITH JACK STANDS OF ADEQUATE CAPACITY.

DANGER - AVOID DEATH - WHEN TESTING THE CONTROLLER, DO NOT TOUCH HIGH VOLT-AGE CONNECTIONS EXCEPT WITH PROPER TEST EQUIPMENT. WHEN WORKING INSIDETHE CONTROL PANEL, USE THE FOLLOWING PROCEDURE TO DISCHARGE THE CAPACI-TORS INSIDE THE CONTROLLER.

1. TURN THE IGNITION KEY ON.

2. DISCONNECT THE BATTERY.

3. WAIT 10 SECONDS, THEN TURN THE KEY OFF.

DIAGNOSTICS:

The SC2000 controller in your M3 Tow Tractor contains a powerful fault diagnostic system that must beused in conjunction with a portable electronic diagnostics computer. This device, referred to in thefollowing pages as a "handset" has a modular connector that connects directly to the controller. Thehandset is sold separately, but need not be purchased with each M3 tractor. Rather, one handset willprobably be sufficient for your needs in diagnosing and servicing your entire Tug Model M3 Tow Tractorfleet.

If the tractor will not drive, and resetting the shifter, handbrake e-stops and recycling the keyswitch failsto clear the problem, the handset or controller fault code should be used first to diagnose the problem.The controller will flash out "fault codes" when an error is detected. The diagnostic light is located onthe end of the controller closest to the front of the vehicle. The telephone-type plugs for plugging thehandset in are also located there. (See Figure 1.)Pro

perty

of A

mer

ican

Airline

s


Diagnostic LED

Handset Plugs

Prope

rty o

f Am

erica

n Airli

nes


II. TROUBLESHOOTING (CONT)

A. CAN CONTROLLER

A sophisticated yet easy to use hand held adjustment unit, called the Can Controller is used tomake adjustments to the controller and select configurations. The CAN Controller is also used asa diagnostic tool displaying the status of all voltages, currents and temperatures within thecontroller together with the condition of all the controllers switch and analogue inputs.

The diagram below describes how the CAN Controller is used. The left and right arrows movebetween screens on the same level. The up and down arrows move between levels and the (+)and (-) buttons increment or decrement the parameters by the amount indicated in the STEPcolumn.

Prope

rty o

f Am

erica

n Airli

nes



B. TRACTION PERSONALITIES (CONTROLLER ADJUSTMENTS)

Cal. Parameter Adjusted Min Settings Max. SettingsMax Settings Step Size Factory SettingsRef. (All Units) (500A units) (650A units) (all units) (all units)

1.1.1 Current Limit Min. Setting 500A 650A 10 Amps 500A1.1.2 Acceration Delay Max. Setting 5.0S 5.0S 0.1 Secs 2.4 Secs1.1.3 Deceleration Delay Max. Setting .05S .05S 0.1 Secs 0.1 Secs1.1.4 Creep Speed (all units) 25% 25% 1.00% %1.1.5 Maximum speed (500A units) 100% 100% 1.0~ 100o1.1.6 Cutback Speed 1 (650 A units) 100% 100% 1.00% 25%1.1.7 Acceleration Delay1 50A 5.0S 5.0S 0.1 Secs 4.0 Secs1.1.8 Cutback Speed 2/Inch Speed 0.1S 100/25% 100/25% 1.00% 40%1.1.9 Acceleration Delay 2 0.1S 5.0S 5.0S 0.1Secs 5.0 Secs1.1.10 Direction Brake Current 0% 500A 650A 10 Amps 50 Amps1.1.11 Footbrake Current p% 500A 650A 10 Amps 70 Amps1.1.12 Neutral Brake Current 0% 500A 650A 10 Amps 40 Amps1.1.13 Bypass Over Current 0.1S 750A 970A 10 Amps 600 Amps1.1.14 Field weak Pull In p% 500A 650A 10 Amps ---1.1.15 Field Weak Drop Out 0.1S 500A 650A 10Amps ---1.1.16 Power Steer Delay 50A 50S 50S 1.0 Secs 10 Secs1.1.17 Seat Switch Delay 10A(0 disables) 5.0S 5.0S 0.1 Secs 1.5 Secs1.1.18 Regen Speed Factor 10A(0 disables) 255% 255% 1.0~o 1501.1.19 Brake Constant Factor 10A(0 disables) 25.5x 25.5x .01x 0.91.1.20 Accelerator Zero Level 50A 5.5V 5.5V 0.1 Volts 3.4 V1.1.21 Accelerator Full Level 50A 5.5V 5.5V 0.1 Volts 0.1V1.1.22 Footbrake Pot Zero Level OS 5.5V 5.5V 0.1 Volts 5.0V1.1.23 Footbrake Pot Full Level OS 5.5V 5.5V 0.1 Volts 2.0V1.1.24 Economy Pot Zero Level 0% 5.5V 5.5V 0.1 Volts ---1.1.25 Economy Pot Full Level Ox 5.5V 5.5V 0.1 Volts ---1.1.26 Contactor Chopping Select OV On off

Current Limit -Maximum allowable motor current.Acceleration Delay -Time taken to ramp up from 0 to 100% on.Deceleration delay -Time taken to ramp down from 100% to 0% on.Creep Speed -Minimum applied % on when drive first selected.Maximum Speed -Maximum allowable % on.Cutback Speed 1 & 2 -Maximum allowable % on when cutback switches active, or inching.Accel. Delay 1 & 2 -Independently adjustable accel. delays during speed cutbacks.Dir. Brake Current -Maximum braking current during direction switch change.Footbrake Current -Maximum braking current in neutral when F. Srake switch activeNeut. Brake Current -Maximum braking current in neutralBypass Over Current -Maximum allowable current in Bypass before contactor opens.F.W. Pull In Current -F.Weak contactor allowed to pull in at currents ~ pulll in levelF.W Drop out Curr. -F. Weak contactor will drop out at current ~ drop out levelPower Steer Delay -Delay after power steer trigger removed until contactor opensSeat Switch Delay -Delay after seat switch opens until pulsing is inhibited.Regen Speed -Regen attempted at lower speeds (Low Nos.) or higher speeds (High Nos.) used to prevent

delays for unsuccesful regen attempts at low speedsBrake Factor -Multiplication factor used to scale regen currents into end plug currents. E.g. Regen neut

brake=100A, factor=0.8, plug current at end of cycle=80A.Zero Levels (3 off) -Used to select minimum voltage input level for function.Full Levels (3 off) -Used to select maximum voltage input level for function.

Prope

rty o

f Am

erica

n Airli

nes


C. TRACTION FAULT MESSAGES

Message No. of Flashes Description Check

OK (on) Traction Operational N/A“Sequence Fault” (2) Direction or FSl sw at power up Dir and FS1 in neutral, Wiring“2 Dir Fault” (2) Two directions selected together Only one direction selected, Wiring

“SRO Fault” (2) Dir sw selected >2secs after FSl Dir first then FS1, FS1 wiring“Seat Fault” (2) Drive selected and no seat sw Ciose seat sw, wiring“Inch Fault” (2) Inch sw at power up, or both Both in neutral, or only one switch

selected“Mosfet s/c” (3) Bypass cont. S/C or Mosfet S/C Bypass welded, Wiring, Mosfets s/c

“Forward o/c” (4) Forward contactor didn’t close Coil wiring, Cont. Wiring Tips,Motor o/c

“Reverse o/c” (4) Reverse contactor didn’t close Coil wiring, Cont. Wiring & Tips,Motor o/c

“Regen o/c” (4) Regen contactor didn’t close Coil wiring, Cont. Wiring Tips,Motor o/c

“Contactor s/c” (4) Fwd or Rev cont. short circuit Welded tips & Contactor wiring“Forward s/c” (4) Forward contactor didn’t open Welded tips & Contactor wiring“Reverse s/c” (4) Reverse contactor didn’t open Welded tips 8 Contactor wiring“Regen s/c” (4) Regen contactor didn’t open Welded tips Contactor wiring“Capacitor Fault” (5) Main caps not charging at power Power wiring or Charge resistor o/c

Up“Accel Fault” (6) Accel. pedal at power up or wire Pedal not pressed, Wire off, Wiring

off“Battery Low” (7) Battery <Low Battery personality Correct Batt. Voltage, Discharged

battery“Thermal Cutback” (8) Traction heatsink above 75' C

Heatsinking, Mounting, Surface’s“Coil s/c” (9) A contactor coil s/c or Pin connected directly to B+ve, coil

misconnected s/c“CRC error” (1) Personality or other config error Reconfigure and check all personali-

ties“Failed” (off) Controller unable to autofailsafe Wiring

Prope

rty o

f Am

erica

n Airli

nes



D. STATUS

Status indicators provide information on the voltages and currents of various components bothwithin the controller and throughout the tractor. The normal status readings available are asfollows:

Key on - Not DrivingBattery Voltage: 0 - 127 volts. 80-86 voltsTraction Motor Voltage Left: 0 - 127 volts. 0 voltsTraction Motor Voltage Right: 0 - 127 volts. 0 voltsTraction Motor Current Left: 0 - 1200 Amps. 0 ampsTraction Motor Current Right: 0 - 1200 Amps. 0 ampsTraction Controller Temp Left: 30°C - 225°CTraction Controller Temp Right: 90°C - 225°CTraction MOFSET Voltage Left: 0 - 127 Volts. 11 - 12 voltsTraction MOFSET Voltage Right: 0 - 127 Volts. 11 - 12 voltsCapacitor Voltage: 0 - 127 Volts: 80 - 86 voltsKey Switch Hours: 0 - 65279.9 hoursTraction Pulsing Hours: 0 - 65279.9 hours

E. TEST

The test section allows the technician to troubleshoot the tractor by observing the inputs that thecontroller is receiving. The following test modes are available:

Accelerator %Accelerator voltageFootbrake %Footbrake voltageEconomy % (not used)Forward switchReverse switchFS1SeatHandbrakeSpeed cutback 1Speed cutback 2Power steer triggerInch forwardInch reverseSoftware versionPro

perty

of A

mer

ican

Airline

s


F. SC2000 FAULT FINDING FLOW CHARTS

1. Two Flash Fault (2FF) - Procedure Fault

CAN Calibrator Display Message CONDITION CHECK

Direction or FS1 1. Direction & FS1 are inSequence Selected at Key Neutral at Key Switch On Fault? Switch on. 2. Wiring is Correct

1. Only One direction 2 DIR FWD and REV selected. Fault? Selected together 2. Wiring

SRO Dir. selected <2 secs 1. Direction first, then FS1. Fault? after FS1. 2. FS1 Wiring

Seat Drive selected and no 1. Select seat switch Fault? seat switch. before drive.

2. Wiring

Inch Inch switch selected 1. Both inch switches Fault? at power up or both are in neutral.

selected. 2. Wiring

YES

NO

YES

NO

YES

NO

YES

NO

YES

Prope

rty o

f Am

erica

n Airli

nes



2. Three Flash Fault (3FF) - Bypass Contactor Welded


1. Bypass contactor 1. Direction & FS1 are inMOFSET Short circuit. Neutral at Key Switch On S/C?

2. Mofsets short 2. Power and control circuit wiring for shorts.

3. Mofset short circuit.Replace controller.

YES

Prope

rty o

f Am

erica

n Airli

nes


YES

NO

YES

NO

YES

NO

3. Four Flash Fault (4FF) - Contactor Fault or Motor Open Circuit (O/C) - Contactor Fault or Motor Short Circuit (S/C)


1. Contactor coil wiring.Forward Forward contactor 2. Contactor power cable O/C? did not close. wiring.

3. Contactor tips.4. Open Circuit Motor.5. Replace Controller.

Reverse Reverse contactor O/C? did not close.

Regen Regen contactor O/C? did not close.

Prope

rty o

f Am

erica

n Airli

nes


YES

NO

YES

NO

YES

NO



3. Four Flash Fault (4FF) - Contactor Fault or Motor Short Circuit (cont)


1. Welded contactor tips. Contactor Forward or Reverse 2. Contactor power cable S/C? contactor short circuit. wiring.

3. Motor for armature tofield short circuit.

4. Short to frame andbattery leakage.

5. Replace Controller.

Forward Forward contactor S/C? did not open.

Reverse contactorReverse did not open. S/C?

Regen contactor Regen did not open. S/C?

YESPrope

rty o

f Am

erica

n Airli

nes


YES

F. SC2000 FAULT FINDING FLOW CHARTS (CONT)

4. Five Flash Fault (5FF) - Capacitor Fault


1. Power cable wiring. Capacitor Main capacitors not 2. Charge resistor Fault? charging at power up. open circuit.

3. Replace controller.field short circuit.

Prope

rty o

f Am

erica

n Airli

nes



5. Six Flash Fault (6FF) - Accelerator Fault


1. Accelerator pedal 1. Accelerator pedal is atAcceler. depressed with rest at key switch on. Fault? key switch on.

2. Accelerator wire off.2. Accelerator wireoff. 3. Wiring

4. Replace controller.

YES

Prope

rty o

f Am

erica

n Airli

nes



6. Seven Flash Fault (7FF) - Low Battery Voltage


1. Correct battery voltage.Battery Battery Voltage < low Low? battery personality 2. Power connections,

fuses, etc.

3. Battery charge level.

4. Battery leakage to truckframe.


YES

Prope

rty o

f Am

erica

n Airli

nes




7. Eight Flash Fault (8FF) - Over Temperature


1. Current limit setting.Thermal Traction heatsink > 75°C.Cutback? 2. Mounting and heatsink of

controller.

3. Bypass operating.

4. Application is correct.


YES

Prope

rty o

f Am

erica

n Airli

nes



8. Nine Flash Fault (9FF) - Accelerator Fault


1. Contactor coil 1. Contactor coil drive pin Coil short circuit. connected directly to B+. S/C?

2. Contactor coil 2. Contactor coil shortcircuit.

YES

Prope

rty o

f Am

erica

n Airli

nes




9. One Flash Fault (1FF) - Personality or configuration error.


CRC Personality or Reconfigure and check Error? configuration error. all personalities.

YES

Prope

rty o

f Am

erica

n Airli

nes



10. LED off - Unit will not power up or controller faulty.


1. Battery connected and Coil Controller unable to keyswitch on. S/C? auto-failsafe check.

2. Fuses ok.

3. Supply wiring.

4. Replace controller.*

*Before replacing Controller:

1. Disconnect battery and discharge capacitors2. Remove all power cables except B+ and B-.3. Remove 24 pin input plug on the end of the controller.4. Unplug the coil wires from the main.5. Reconnect the battery and turn on the keyswitch.6. This procedure isolates the controller from all imputs. It the unit now completes the self-check, reconnect inputs one-by-one until the area causing the fault is identified.7. If the unit does not complete the self-check, replace the controller.

YES

Prope

rty o

f Am

erica

n Airli

nes


COMPLAINT CAUSE CORRECTION

1. Partial or complete loss of12V power (automotivesystems)

2. No 12v at circuit breaker.

DANGER! - HIGH VOLTAGE.

II. TROUBLESHOOTING (CONT.)

G. 72/80 VOLT SYSTEMS

(a) Main Switch in "Off" posi-tion.

(b) No 80v power going intoconverter.

(c) No power to supply side ofcircuit breakers.

(d) Circuit breakers tripped.

(e) 12v wiring problem.

(a) Converter or converter fusebad.

(a) Turn main power switch on.

(b) Check inline fuse.

(c) Go to step 2 (below).

(d) Replace bad breakers.

(e) Troubleshoot 12v wiring.

(a) Replace converter or fuse.

Prope

rty o

f Am

erica

n Airli

nes



II. TROUBLESHOOTING (CONT.)

1. Excessive pedal travel orpedal goes to floor consis-tently.

2. Brake pedal feels spongywhen fully applied.

(a) Low fluid level

(b) Hydraulic system.

(c) Loose or improper attach-ment of pedal, pedalsupport booster & mastercylinder.

(d) Misaligned anchor plate.

(a) Low fluid level

(b) Front wheel bearing out ofadjustment.

(c) Disc brake caliper attach-ment loose.

(a) Add fluid, bleed system,check for leaks.

(b) Refer to master cylinder.

(c) Repair or replace as re-quired.

(d) Refer misaligned disc brakeanchor plate diagnosis.

(a) Add fluid, bleed system,check for leaks.

(b) Adjust front wheel bearings

(c) Replace or tighten asrequired.

Prope

rty o

f Am

erica

n Airli

nes



3. Noise at wheels whenbrakes are applied-squeaksor chatter.

4. Brakes pull to one side.

II. TROUBLESHOOTING (CONT.

(a) Worn or scored brake rotors& pads.

(b) On disc brakes- missing ordamaged brake pad insula-tors

(c) Burrs or rust on caliper thatwould obstruct seating ofshoe to caliper.

(d) Dirty, greased or glazedlinings.

(a) Unequal air pressure intires.

(b) Grease or fluid on lining.

(c) Loose or missing disc brakecaliper attaching bolts.

(d) Restricted brake lines orhoses.

(a) Inspect, repair or replace asrequired.

(b) Replace disc brake pads.

(c) Clean or deburr caliper.

(d) Clean or replace.

(a) Inflate tires to correctpressure.

(b) Clean, sand &/ or replacelinings.

(c) Replace missing bolts.Tighten to proper torque.

(d) Repair or replace as re-quired.

Prope

rty o

f Am

erica

n Airli

nes



1. Parking brake will not hold.

2. Parking brake will notrelease or fully return.

3. Parking brake lever hard topull up.

I. PARKING BRAKE

(a) Parking brake cable out ofadjustment.

(b) Parking brake linkage,release lever & clevis.

(a) Manual release brakecontrol components bindingor damaged.

(b) Parking brake linkage &cable binding.

(c) Worn or damaged rearbrake components.

(a) Brake handle out of adjust-ment.

(b) Frozen or damaged brakecable.

(a) Adjust parking brake cable.

(b) Repair or replace linkage asreqd.

(a) Repair or replace manualparking brake control.

(b) Repair or replace as re-quired.

(c) Check rear brake calipers &cable linkage. Repair asrequired.

(a) Adjust or repair.

(b) Light taps with a mallet mayfree cable & brakes, other-wise apply warm air from aground equipment heater.

Prope

rty o

f Am

erica

n Airli

nes


J. 12 VOLT LADDER SCHEMATIC

Prope

rty o

f Am

erica

n Airli

nes

Chapter 2: Maintenance Aug, 1997 Section 2-2 p. 23

K. M3 COMPLETE WIRING DIAGRAM

Prope

rty o

f Am

erica

n Airli

nes


Prope

rty o

f Am

erica

n Airli

nes


III. REMOVAL/INSTALLATION

The following procedures for removal and installation of vehicle components outline the steps andprecautions to take when removing items for replacement or repair.

WARNING! WHEN TESTING AN ELECTRIC VEHICLE, JACK THE DRIVE WHEELS OFF THEGROUND AND SECURE IN THIS POSITION WITH JACK STANDS OF ADEQUATE CAPACITY.

DANGER - AVOID DEATH - WHEN TESTING THE CONTROLLER, DO NOT TOUCH HIGH VOLT-AGE CONNECTIONS EXCEPT WITH PROPER TEST EQUIPMENT. WHEN WORKING INSIDETHE CONTROL PANEL, USE THE FOLLOWING PROCEDURE TO DISCHARGE THE CAPACI-TORS INSIDE THE CONTROLLER.




WARNING: ALWAYS REVIEW SAFETY PRECAUTIONS PRIOR TO PERFORMING WORK ONTHIS EQUIPMENT.

A. OPERATOR/PASSENGER SEAT REMOVAL

1. Slide seat all the way forward.

2. Remove rear (2) mounting bolts

3. Slide seat rearward.

4. Remove front (2) mounting bolts.

5. Detach seat switch wiring.

6. Remove seat

B. OPERATOR/PASSENGER SEAT INSTALLATION

Reverse removal procedure.

Prope

rty o

f Am

erica

n Airli

nes

Chapter 2: Maintenance Sept 1995 Section 2-3 p. 2

III. REMOVAL/INSTALLATION (CONT)

C. SHIFTER ASSEMBLY REMOVAL

WARNING! DISCONNECT BATTERY AND DISCHARGE CAPACITORS PRIOR TO BEGINNING THIS OPERATION.

1. Unscrew shifter knob.

2. Remove rubber boot retainer ring & rubber boot.

3. Remove (2) mounting fasteners.

4. Slide shifter down through mounting hole.

5. Remove wiring.

D. SHIFTER ASSEMBLY INSTALLATION

1. Hold shifter assembly without knob UNDER mounting hole in approximate mountedposition. Rotate shaft toward front of vehicle to reveal wiring attachment points. Attachwiring according to diagram.

2. Rotate shifter to upright position. Slide shifter up through mounting hole.

3. Mount assembly using (2) mounting fasteners

4. Install rubber boot & retainer ring.

5. Thread on shifter knob.

E. MAIN POWER ("IGNITION") SWITCH REMOVAL

WARNING! DISCONNECT BATTERY AND DISCHARGE CAPACITORS PRIOR TO BEGINNING THIS OPERATION.

1. Remove console bolt, open console door.

2. Disconnect wiring.

3. Unthread outside retainer ring.

4. Remove switch.

F. MAIN POWER ("IGNITION") SWITCH INSTALLATION

1. Remove outside retainer ring from switch to be installed (if applicable).

Prope

rty o

f Am

erica

n Airli

nes


2. Slide switch into console door switch mounting hole.

3. Thread on outside mounting ring.

4. Attach wiring.

G. MASTER CYLINDER REMOVAL

1. Open Console door.

2. Remove brake lines from cylinder body.

3. Plug brake line ports or drain brake fluid into appropriate container.

4. Remove (2) mounting bolts and nuts.

5. Slide master cylinder off of push rod.

H. MASTER CYLINDER INSTALLATION

1. Open Console door.

2. Slide master cylinder onto push rod.

3. Mount cylinder body using (2) mounting bolts and nuts.

4. Unplug cylinder brake line ports.

5. Attach brake lines to brake line ports.

I. STEER VALVE REMOVAL

1. Remove Steering wheel. (see appropriateprocedure)

2. Disconnect horn wires.

3. Remove (4) mounting bolts.

4. Slide steer valve assembly down through hole.

5. Remove hydraulic lines.

Figure 1

Prope

rty o

f Am

erica

n Airli

nes


III. REMOVAL/INSTALLATION(CONT)

J. STEER VALVE INSTALLATION

1. Attach hydraulic lines (see diagram) to steer valve.

2. Align steer valve with column so that line ports face toward front of vehicle. Wireattachment points should be on driver's right side of column.

3. Slide steer valve assembly up through mounting hole. Hold assembly together as bolts areworked through holes and column flange, and into steer valve.

4. Tighten (4) mounting bolts.

5. Connect horn wires.

6. Attach steering wheel. (see appropriate procedure)

K. TIRES AND WHEELS

1. Rear Tire and Wheel Removal/Installation

CAUTION: DO NOT REMOVE THE HUB NUTS FOR WHEEL REMOVAL.THE HUB NUTS ARE REMOVED FOR HUB REPAIR ONLY.

(a) Jack rear wheels off the ground using normal jacking procedures (i.e.: chockother tires, engage parking brakes, etc.)

(b) Remove the nine (9) lug nuts which secure the wheel to the drive axle hub andremove the wheel.

(c) Remove the tire for repair or replacement as required, using proper tire tools.

(d) Install the new or repaired tire onto the wheel.

(e) Install the wheel to the hub with nine (9) lug nuts and torque to 125 ft. - lbs.

2. Front Tire and Wheel Removal/Installation

(a) Jack the front wheels off the ground using normal jacking procedures (i.e.: chockother tires, engage parking brake, etc.).

WARNING: IF WHEEL IS EQUIPPED WITH RETAINING RING, TIRE MUST BECOMPLETELY DEFLATED. CAUTION MUST BE TAKEN WHEN REMOVINGRING, IT HAS A TENDENCY TO “FLY” OFF WHEN REMOVING.

(b) Remove the five (5) lug nuts which secure the wheel to the steer axle hub andremove the wheel.

Prope

rty o

f Am

erica

n Airli

nes


(c) Remove the tire for repair or replacement, as required.

(d) Install the new or repaired tire on the wheel.

(e) Install retaining ring, if required.

(f) Install the wheel to the hub with five (5) lug nuts and torque to 125 ft. - lbs.

L. ACCELERATOR PEDAL REMOVAL:

Note: Accelerator Pedal Assembly on the Tug model M3 is a specialized Morse control thatcombines the pedal and cable assemblies into a single assembly. Removal and installationinstructions in this section assume complete removal of this assembly. Refer to "acceleratorcable removal/installation" procedure for separation of cable from pedal assembly.

WARNING! DISCONNECT BATTERY AND DISCHARGE CAPACITORS PRIOR TO BEGINNING THIS OPERATION:




1. Remove (3) fasteners at base of pedal assembly.

2. Remove left side service access panel.

3. Locate accelerator box. Loosen cable nut from mount bracket.

4. Disconnect cable tip from accelerator box lever.

5. Clip all visible plastic cable ties with wire cutters.

6. Remove console cover plate (between seats).

7. Open console access door.

8. Clip all visible plastic cable ties with wire cutters.

9. Work cable from electrical service area, back through console area and out through pedalmount opening.

10. Remove pedal/cable assembly.

Prope

rty o

f Am

erica

n Airli

nes



M. ACCELERATOR PEDAL INSTALLATION:

1. Remove left side service access panel.

2. Remove console cover plate (between seats).

3. Open console access door.

4. Work cable through pedal mount opening, through console area and out to electricalservice area.

5. Connect cable tip to accelerator box lever.

6. Locate accelerator box. Slide cable into cable mount bracket. Tighten nut.

7. Tie cable assembly to electrical cable and other structures along route, leaving enoughextra cable in console to allow removal of pedal if needed.

8. Fasten pedal to floorboard (3 fasteners) at base of pedal assembly.

9. Reattach all access panels.

N. HYDRAULIC STEERING PUMP REMOVAL





CAUTION! SIDE PANELS ARE HEAVY! REMOVE CAREFULLY

1. Remove right side access panel.

2. Disconnect electrical wiring.

3. Remove (4) mounting bolts: Use long extension rachet and matching wrenches belowtractor.

CAUTION: WIPE ALL CONNECTIONS CLEAN PRIOR TO OPENING SYSTEM.

CAUTION: CAP OR PLUG ALL OPEN PORTS AND LINES.

Prope

rty o

f Am

erica

n Airli

nes


NOTE: USE BACK UP WRENCHES ON ALL MATING FITTINGS.

4. Gently rotate pump to reveal access to hydraulic line connections.

5. Remove hydraulic lines at elbows.

6. Remove pump & reservoir assembly.

O. HYDRAULIC STEERING PUMP INSTALLATION

1. Place pump & reservoir assembly into floor of right side service bin, reservoir end towardrear of vehicle.

2. Attach hydraulic lines at elbows, long line rearward and short line at pump.

3. Attach assembly to floor using (4) mounting bolts: Use long extension rachet and matchingwrenches below tractor.

Figure 2

Power Brakes

Power Steering

Prope

rty o

f Am

erica

n Airli

nes



O. HYDRAULIC STEERING PUMP INSTALLATION (CONT)

4. Connect electrical wiring.

5. Top off hydraulic fluid in reservoir.

6. Replace right side access panel.

P. BRAKE BOOSTER PUMP REMOVAL

WARNING! DISCONNECT BATTERY AND DISCHARGE CAPACITORS PRIOR TO BEGIN-NING THIS OPERATION:




CAUTION! SIDE PANELS ARE HEAVY! REMOVE CAREFULLY!

1. Remove right side access panel by removing (4) hex socket screws.

2. Disconnect wiring from pump.

3. Disconnect wiring from pressure switch.

4. Remove front and rear hydraulic lines using box-end wrenches.

5. Remove (4) mounting bolts.

6. Remove brake booster assembly.

Q. BRAKE BOOSTER PUMP INSTALLATION

1. Remove right side access panel by removing (4) hex socket screws.

2. Place brake booster assembly on platform in right side service compartment. Pressuresensor switch must face rear of vehicle.

3. Align mounting holes; install mounting hardware. Tighten securely.

4. Attach front and rear hydraulic lines using box-end wrenches. Refer to figure (2).

5. Connect wiring to pump.

Prope

rty o

f Am

erica

n Airli

nes


6. Connect wiring to switch.

7. Top off brake fluid reservoir.

R. REPLACE DRIVE MOTOR BRUSHES

Note: Drive motor brushes are arranged in four sets of two around axis of drivemotors. Sets are placed at 12: o'clock, 3 o'clock 6 o'clock and 9 o'clock. (Seeillustration). Due to their placement in the drive tube, each set of brushes must beaccessed from a different angle. Provisions have been made in the design of theM3 Tow Tractor so that all four brush placements in each of the two drive motorsare accessible without removing the drive motors.

WARNING! DISCONNECT BATTERY AND DISCHARGE CAPACITORS PRIOR TOBEGINNING THIS OPERATION:




1. Note: Motor cover is the sloped access panel located in the center-rear of the vehicle justbehind the battery. Remove four bolts. Remove motor cover.

2. Remove battery. (See battery removal procedure)

3. Jack rear wheels off the ground using normal jacking procedures (i.e.: chock other tires,engage parking brakes, etc.) Jack rear of vehicle high enough to allow access beneathvehicle. Place rear end of vehicle on jack stands. Remove Jack.

4. From beneath vehicle, locate clamps on motor contact protector bands. Release clampson both motors. Slide clamps toward center of vehicle to reveal brushes.

5. Use flat blade screwdriver to remove brush lead screw on one brush. (Note: First set is the6 o'clock position brush set.)

6. Pull spring clip away from brush and slide brush out of guide.

7. Repeat procedures 4 & 5 for other brush.

8. Reinstall or replace brushes in reverse order. (Always replace all brushes on a motor.)

9. For convenience, it is recommended that both motor brushes are replaced at the sametime. Replace second motor brush set.

10. From rear of vehicle, replace rearward sets of brushes.

Prope

rty o

f Am

erica

n Airli

nes



R. REPLACE DRIVE MOTOR BRUSHES (CONT)

11. From top of vehicle, replace third set of brushes.

12. Access fourth set through access hatch in battery compartment. Replace fourth set ofbrushes in both drive motors.

13. Replace brush protection rings.

14. Replace access panels.

15. Jack vehicle back down to floor.

16. Install and reconnect battery.

S. DRIVE MOTOR(S) REMOVAL

WARNING! DISCONNECT BATTERY AND DISCHARGE CAPACITORS PRIOR TOBEGINNING THIS OPERATION.


2. Disconnect all drive motor wiring.

3. Jack rear wheels off the ground using normal jacking procedures (i.e.: chock other tires,engage parking brakes, etc.) Jack rear of vehicle high enough to allow access beneathvehicle. Place rear end of vehicle on jack stands. Remove Jack.

4. Remove the nine (9) lug nuts which secure the wheel to the drive axle hub and remove thewheel.

5. Remove brake calipers by removing (2) caliper mounting bolts. Slide caliper upward offrotor. (Note: It may not be necessary to completely disconnect caliper. The aim here is toremove the rotors to access the drive motor mounting bolts. It may, however, be necessaryto remove the park brake cable from the caliper.)

6. Remove rotor.

7. From behind hubs, loosen and remove (4) drive motor mounting bolts.

8. From motor cover access, slide drive motor toward center of vehicle until the motor spindledisengages from the hub. Tip end upward and carefully lift motor out of drive tube.

9. Repeat procedure for other drive motor, if necessary.

Prope

rty o

f Am

erica

n Airli

nes


T. DRIVE MOTOR(S) INSTALLATION






2. From motor cover access, tip end upward and carefully slide drive motor, spline end first,into center of hub. Note! Make sure that connection posts face upward. Rotate the hubslightly as needed until the motor shaft splines line up with hub opening splines.

3. Note: It is assumed that with motor removed, the vehicle is on jack stands and the brakerotor(s) removed. Rotate drive motor slightly as needed to align mounting holes. Threadin mounting bolts. Tighten each bolt evenly. Retighten each to 40 ft-lbs.

4. Install rotor.

5. Slide caliper over rotor and mounting structure. Align mounting holes Thread in (2) calipermounting bolts. Tighten securely, and reconnect park brake cable.

6. Connect all drive motor wiring.

7. Repeat procedure for other drive motor, if necessary.

8. Replace wheels and tires.

9. Jack vehicle back down to floor.

10. Replace motor cover access panel.

U. CONTACTOR TIPS REMOVAL/REPLACEMENT

Note: Contactors are designed for easy replacement of tips only, as opposed to completereplacement of contactor assembly. Refer to contactor removal/replacement for completecontactor replacement. Refer to controller cabling illustration (figure 3) for individual cableremoval and installation.



Prope

rty o

f Am

erica

n Airli

nes


III. REMOVAL/INSTALLATION

U. CONTACTOR TIPS REMOVAL/REPLACEMENT (CONT)



1. Remove left side service cover.

2. Locate individual contactor or contactors to be serviced.

3. Disconnect all attached electrical cables using 17mm open-end wrench. Rotate conductorbars out of the way if applicable.

4. Remove (2) slot screws from contactor tips cover. Remove contactor tips cover.

Figure 3

Prope

rty o

f Am

erica

n Airli

nes


5. Carefully remove center springs (2) from center post of middle contacts.

6. Slide lower contactor tip set off of insulator posts, replace. Replace center set. Removeupper contactor tips using wrench, replace.

7. Replace inner and outer center springs.

8. Reattach contactor tips cover, thread in and tighten (2) slot screws.

9. Attach electrical cables and conductor bars (if applicable). (Refer to controller cablingillustration (figure 3) for individual cable removal and installation.)

10. Install service compartment cover.

11. Reconnect battery.

12. Test unit thoroughly before returning to service.

V. BATTERY REMOVAL/REPLACEMENT:

1. Discharge Capacitors

2. Disconnect battery

3. Hoist battery from lift loops and remove.

4. Hoist new battery above tractor, carefully lower into place.

5. Connect battery.

W. SERVICE BRAKES REMOVAL/INSTALLATION

Refer to Chapter 3 (Overhaul) Section 3-5 for complete brake Service instructions including thefollowing:

-brake pads-brake rotor -front-brake rotor -rear-brake caliper -front-brake caliper -rear

X. PLANETARY REDUCTION HUBS REMOVAL




Prope

rty o

f Am

erica

n Airli

nes


III. REMOVAL/INSTALLATION (CONT)

X. PLANETARY REDUCTION HUBS REMOVAL (CONT)


1. Chock front tires. Jack rear of tractor, secure with jack stands beneath rear bumper.

2. Remove tire.

3. Follow instructions for removal of drive motor(s). Drive motors must be removed to accesshub mount plates.

4. Remove (6) hub mount bolts.

5. Insert a flat balde screwdriver between the hub and hub mounting ring, and gently pry thehub out, gradually working around the ring.

Y. PLANETARY REDUCTION HUBS INSTALLATION

Note: this procedure assumes that drive motors and old hub(s) have been removed and thattractor is securely jacked and mounted. Make sure that the hub and the tube mounting surfaceare clean and free of paint. Coat mating surfaces with thermal transfer grease.

1. Clock hub so that mounting holes are at 3, 6, 9 & 12 o'clock.

2. Align hub plate bolt holes with drive tube end bolt holes. Thread in (6) hub mount bolts.Tighten securely (at least 80 ft-lbs).

3. Follow procedures to install drive motor(s).

4. Install brake rotor.

5. Attach brake caliper.

5. Rotate hub so that side fill hole is 1" below horizontal. Fill hub with quality synthetic gearoil (Amzoil 90 or equivalent).

6. Install tire.Prope

rty o

f Am

erica

n Airli

nes


IV. ADJUSTMENTS

A. PARK BRAKE

1. Discussion

When properly adjusted, the parking brake will prevent the M3 Tow Tractor from rollingwhen parked on a 15% grade. Engaging a properly adjusted parking brake should notrequire an excessive amount of force, however some slight resistance will be present whenengaging.

2. Procedure

a. If parking brake hand lever is equipped with a locking set screw, loosen the setscrew.

b. To tighten parking brake, turn knurled knob at the end of the hand lever clockwise.

c. To loosen parking brake, turn knurled knob at the end of the hand lever counter-clockwise.

d. If parking brake hand lever is equipped with a locking set screw, tighten the setscrew.

B. SERVICE BRAKE ADJUSTMENT

Note: Service brake is factory preset for safety. Do not readjust until necessary due to otherbrake-related service.

1. Loosen stop nut on brake rod.

2. The Service brake pedal height can be adjusted by threading the clevis on the mastercylinder.

C. VERTICAL HEADLIGHT ADJUSTMENT

1. Loosen the nut on the horizontal bolt.

2. Aim headlight in desired direction.

3. Tighten the nut.

Prope

rty o

f Am

erica

n Airli

nes


IV. ADJUSTMENTS

D. FRONT SPRING PRELOAD ADJUSTMENT

1. Discussion:

Due to the variations in battery weight available in the M3, the front springs should beadjusted to provide the appropriate front wheel camber. The appropriate camber setting is+1 degree past vertical (see figure 1). Adjusting the front spring preload adjusts thecamber of the front wheels:

2. Procedures:

1. Position tractor on levelpavement.

2. Remove center cover platebetween seats.

3. Attach camber gauge to rightside wheel hub (see figure 2).

4. Note tensioning bolts locatedin recess above springs. Usea deep well socket to loosenbolt and lock nut.

Note: Adjustments andmeasurements should bemade without the added weightof driver or passenger.

5. Adjust bolt down (tighten) toadjust camber in positive direction. Adjust bolt up (loosen) to adjust camber in

Figure 2

Figure 1

Prope

rty o

f Am

erica

n Airli

nes


negative direction. Adjustments should be incrementally small.

6. Roll tractor forward and then back a few feet to allow adjustments to balance out oftire grip. (Be sure to remove camber gauge prior to rolling tractor.)

7. Repeat steps 5 & 6 as necessary.

8. Repeat adjustment for left side of tractor.

9. Repeat right and left gauge checks before concluding.

10. Tighten lock nuts; replace console access cover.

E. BLEED REAR BOOSTED BRAKES

The rear brakes on the M3 tow tractor are boosted by a hydraulic pump located in the right sideservice compartment. Whereas the bleeding process for the rear brakes is straightforward, thereare some considerations to bleeding the brake lines that are unlike standard brakes:

1. The front (larger) reservoir compartment of the master cylinder actually provides thebraking to the rear system.

2. This brake line from the master cylinder provides the braking actuation to the brakebooster. This "center" line between the master cylinder and the brake booster can be bledin the traditional manner via a bleed valve located on the brake booster.

3. The rear lines between the booster and the rear calipers require special procedures asfollows:

NOTE: THREE PEOPLE ARE REQUIRED TO BLEED REAR BRAKE LINES.

(a) With the power switch in the ON position, person #1 must depress the brake pedal.

Note: Unlike traditional brake bleeding techniques, the operator must NOT pump thebrake pedal. Only a steady, partial pressure is required on the brake pedal toactuate the brake booster pump.

(b) A second person is required to keep a constant supply of brake fluid flowing into thebrake booster reservoir. The brake booster can empty the reservoir VERYQUICKLY, and must be constantly replenished during the bleeding process.

(c) The third person must loosen and tighten the bleed valves located at the rear brakecalipers.

IMPORTANT: If the booster pump is accidently allowed to completely empty the reservoir, it willpump air into the rear brake lines. At this point the bleeding process must be started fromthe beginning, in order to purge the air from the lines.

Prope

rty o

f Am

erica

n Airli

nes


IV. ADJUSTMENTS

E. BLEED REAR BOOSTED BRAKES (CONT)

IMPORTANT: DO NOT remove the brake booster reservoir. Doing so will break the sealbetween the reservoir and the pump, and cause leakage.

Prope

rty o

f Am

erica

n Airli

nes


V. INSTRUCTIONS FOR JACKING AND POSITIONING VEHICLE

A. SAFETY PREREQUISITES

1. Use only duty-rated jacks and jack stands. Floor jack should be rated for a minimum oftwo tons. Jack stands should be rated for at least one ton each.

2. Except in emergency situations, tractor should be parked on flat, high quality concretesurface before jacking. DO NOT ATTEMPT TO PERFORM MAINTENANCE ON JACKEDTRACTOR IF PARKED ON SOFT OR WET SURFACE!

B. PROCEDURE

WARNING: IMPROPER JACKING CAN RESULT IN DAMAGE TO THE TRACTOR AND/ORPERSONAL INJURY AND POSSIBLE DEATH.

1. Engage the parking brake and chock the wheels.

2. Position floor jack under front or rear bumper and raise the tractor.

3. Position jack stands under the bumper and lower the loader onto the jack stands.

Prope

rty o

f Am

erica

n Airli

nes


(This Page Intentionally Left Blank)

Prope

rty o

f Am

erica

n Airli

nes

Property of American Airlines Maintenance · 2018-12-03 · Figure 3. CHECK. I. SERVICING B....

Documents

Transcript of Property of American Airlines Maintenance · 2018-12-03 · Figure 3. CHECK. I. SERVICING B....