Service Manual Trucks - General · PDF fileService Manual Trucks Group 72 Volvo Air...

Service ManualTrucks

Group 72

Volvo Air Suspension

VNL, VNM

PV776-TSP27725/1

Foreword

The descriptions and service procedures contained in this manual are based on de-signs and methods studies carried out up to November 97.

The products are under continuous development. Vehicles and components producedafter the above date may therefore have different specifications and repair methods.When this is believed to have a significant bearing on this manual, supplementary ser-vice bulletins will be issued to cover the changes.

The new edition of this manual will update the changes.

In service procedures where the title incorporates an operation number, this is a refer-ence to an S.R.T. (Standard Repair Time).

Service procedures which do not include an operation number in the title are for gen-eral information and no reference is made to an S.R.T.

The following levels of observations, cautions and warnings are used in this ServiceDocumentation:

Note: Indicates a procedure, practice, or condition that must be followed in order tohave the vehicle or component function in the manner intended.

Caution: Indicates an unsafe practice where damage to the product could occur.

Warning: Indicates an unsafe practice where personal injury or severe damage to theproduct could occur.

Danger: Indicates an unsafe practice where serious personal injury or death could oc-cur.

Volvo Trucks North America, Inc.Greensboro, NC USA

Order number: PV776-TSP27725/1

© 97 Volvo Trucks North America, Inc., Greensboro, NC USA

All rights reserved. No part of this publication may be reproduced, stored inretrieval system, or transmitted in any forms by any means, electronic, me-chanical, photocopying, recording or otherwise, without the prior writtenpermission of Volvo Trucks North America, Inc..

ContentsGeneral .................................................................................................... 3

Description ............................................................................................. 3

Specifications ......................................................................................... 5Rear suspension (Air Ride) fastener torque specifications ................... 5Pinion angle specifications .................................................................... 5Suspension Applications ....................................................................... 6

Tools ........................................................................................................ 7Special Tools ......................................................................................... 7Other Equipment ................................................................................... 7

Design and Function ............................................................................. 9General .................................................................................................. 9Volvo Air Suspension Components ..................................................... 10

Spring Bracket ................................................................................. 10Wear Plate ....................................................................................... 10Z-Spring ........................................................................................... 10Radius Spring .................................................................................. 10Crossbeam ...................................................................................... 11Axle Seat ......................................................................................... 11Bottom Plate .................................................................................... 11Top Plate ......................................................................................... 11Air Spring ........................................................................................ 12Link Rod .......................................................................................... 12Leveling/Height Valve ...................................................................... 12Shock Absorber Bracket, Lower ...................................................... 13Shock Absorber Bracket, Upper ...................................................... 13Torque Rod ...................................................................................... 13

Pneumatic Switch Panel ...................................................................... 14Dump Switch Operation .................................................................. 15

Troubleshooting ................................................................................... 17Troubleshooting the Volvo Air Suspension .......................................... 17

Service Procedures ............................................................................. 19Guidelines for Working on the Volvo Air Suspension ......................... 19Volvo Air Suspension Ride Height and Driveline Angle Check (Cal-culation) and Adjustment ..................................................................... 20

Air Suspension Ride Height Check (Calculation) ............................. 21Interaxle U-joint Angle Cancellation Check (Calculation) ................. 22Forward Axle Pinion Angle to Frame Check ..................................... 24

U-bolt Torque Procedure ..................................................................... 25Method 1 (preferred) ......................................................................... 25Method 2 ........................................................................................... 25

Volvo Air Suspension Ride Height Adjustment ................................... 26Volvo Air Suspension Component Replacement ................................ 28Leveling Valve Replacement ............................................................... 28Link Rod Replacement ........................................................................ 29Crossbeam (Pedestal Plate) Replacement ......................................... 31Z-Spring Replacement ......................................................................... 32Radius Spring Replacement ................................................................ 34Torque Rod and Frame Bracket Replacement .................................... 36Spring Hanger (Frame) Bracket Replacement .................................... 37Wear Plate (Pad) Replacement ........................................................... 38Upper Shock Absorber Bracket Removal and Installation .................. 40

1

Lower Shock Absorber Bracket Removal and Installation .................. 40Shock Absorber Removal and Installation .......................................... 42Rear Axle Top Plate/Bottom Plate Removal and Installation .............. 42Air Spring Removal and Installation .................................................... 44Pneumatic switch replacement ............................................................ 45

Removal ............................................................................................. 45Installation ......................................................................................... 45

System Check ...................................................................................... 47Volvo Air Suspension ........................................................................... 47Volvo Air Suspension Ride Height and Driveline Angle Check FlowDiagram ............................................................................................... 48Volvo Air Suspension — Calculation Form ......................................... 49

Operation Numbers

2

Group 726 Volvo Air Suspension General

GeneralDescription

W7000753

This information covers specifications, service proce-dures, ride height adjustments and calculations, andpinion angles for the Volvo Air Suspension. Informationin this manual is essential to maintain proper serviceabil-ity and proper ride height set by the manufacturer for theVolvo Air Suspension.

WARNING

The Volvo Air Suspension is set at the factory. Chang-ing the ride height will affect the driveshaft angles andmay cause driveline vibration and/or shorten compo-nent life.Ride height adjustments must be performed in ac-cordance with all service manual procedures.

3

Group 726 Volvo Air Suspension Specifications

SpecificationsRear suspension (Air Ride) fastener torque specifications

M20 STD 38K 6x4500 ± 75 Nm (369 ± 55 ft-lb)

U-Bolts for SuspensionM22 STD 40K 6x4, 4x2

575 ± 50 Nm (424 ± 37 ft-lb)

Radius Spring to Spring Hanger Bracket M16 275 ± 45 Nm (203 ± 33 ft-lb)

Air Spring Crossbeam (Pedestal) to LeafSpring

M12 105 ± 20 Nm (77 ± 15 ft-lb)

Air Spring to Crossbeam (Pedestal) M12 50 ± 10 Nm (37 ± 7.5 ft-lb)

Torque Rod to Frame-Mounted Bracket M16 320 ± 50 Nm (236 ± 37 ft-lb)

Torque Rod to Axle Housing M16 320 ± 50 Nm (236 ± 37 ft-lb)

Shock Absorber Bracket to Frame M16 320 ± 50 Nm (236 ± 37 ft-lb)

Shock Absorber to Bracket (Upper andLower)

M10 60 ± 10 Nm (44 ± 7 ft-lb)

Bracket for Leveling Valve to Frame M10 60 ± 10 Nm (44 ± 7 ft-lb)

Leveling Valve to Bracket M6 10 ± 1.5 Nm (7 ± 1 ft-lb)

Leveling Valve Control Arm to Lever on Valveand Air Bag Pedestal

M6 10 ± 1.5 Nm (7 ± 1 ft-lb)

Spring Hanger Bracket to Frame M16 320 ± 50 Nm (236 ± 37 ft-lb)

Pinion angle specificationsAXLE PINION ANGLES

AXLE MODEL FIRST AXLE SECOND AXLE(52 in. spacing)

SECOND AXLE(60 in. spacing)

Eaton23080/23105Meritor (Rockwell)RS-23-160/RS-23-186

3.5� - - - - - -

EatonD404

2.5� 10.5� 9.0�

Meritor (Rockwell)RT-40-145

2.5� 12.0� 10.5�

Note: Second tandem axle pinion angle may vary be-cause of frame slope. These are nominal angles.

5

Group 726 Volvo Air Suspension Specifications

Suspension Applications

Available AxlesSuspension

Configuration

MaximumGAWR

Metric Ton (lb)

MaximumGCW

Metric Ton (lb)

Axle Spacingmm (in.)

Required Numberof ParkingChambers Models Metric Ton (lb)

4x29 (20,000)

(1)N/A TWO

EatonMeritor (Rock-

well)

10(23,000)

17 (38,000) 1320 (52") TWO (1st Axle)

18 (40,000)(1) 1320 (52") FOUR

6x4

18 (40,000)(1)

50 (110,000)(2)

1524 (60") FOUR

EatonMeritor (Rock-

well)

18(40,000)

(1) All 6x4 applications at 18 metric ton (40,000 lb) andall 4x2 applications require 22mm diameter U-bolts asstandard. Also, 6x4 applications at 18 metric ton (40,000lb) require heavy wall axle housings. All 6x4 vehicles de-livered outside the United States require 22mm U-bolts(minimum) and the heavy wall axle housing (minimum)regardless of the suspension rating.

(2) GCW (Gross Combination Weight) rating can bereduced by vehicle operating applications, engine horse-power/torque, axle type/model, axle ratio, and/or vehicletire size.

6

Group 726 Volvo Air Suspension Tools

ToolsSpecial ToolsThis air line release tool, part no. J-42189 may be usedto safely disconnect air lines from switches. This tool isavailable from Kent-Moore (telephone: 1–800–328–6657).

W0001198

Other EquipmentThe following tools can be used to ensure proper inclina-tions and/or angles on the Volvo Air Suspension:

The Anglemaster is a digital inclinometer, available fromDana-Spicer (telephone: 419–535–4300).

W7000250

The J38460–A is a digital protractor, available from Kent-Moore (telephone: 800–328–6657).

W7000708

The J38460–25 may be used along with the Kent-Mooredigital protractor or the Dana-Spicer digital inclinometerfor checking pinion angles. It is available from Kent-Moore (telephone: 800–328–6657).

W7000726

7

Group 726 Volvo Air Suspension Design and Function

Design and FunctionGeneral

W7000753

The Air-Ride Suspension has been refined by VolvoTrucks North America. The result of this refinementprocess is the Volvo Air Suspension. The Volvo Air Sus-pension is a rear air suspension with improved ride andincreased durability.

Ride height has a direct relationship with driveline pinionangles. It is very important that the ride height specifica-tions recommended by Volvo Trucks North America aremaintained.

WARNING

The Volvo Air Suspension is set at the factory. Chang-ing the ride height will affect the driveshaft angles andmay cause driveline vibration and/or shorten compo-nent life.Ride height adjustments must be performed in ac-cordance with all service manual procedures.

9


Volvo Air Suspension Components

Spring BracketThe Volvo Air Suspension bracket is a ductile iron castingand includes an internal alignment guide to help centerthe Z-spring within the bracket during initial assembly.

W7000695

Wear PlateThe wear plate (pad) is constructed of the same material(Ultra-High Molecular Weight Polyethylene) as earlierwear plates. This material provides an extremely smoothsurface for the spring to contact and virtually eliminatesthe noise associated with the metal-to-metal contact ofother suspension designs. The Volvo Air Suspensionwear plate mounts with a single fastener into a pocketbetween the vertical legs of the spring bracket.

Note: Wear plates (pads) must be replaced in pairs (leftand right) to avoid excessive stress on the suspension.

W7000739

Z-SpringThe Z-spring has been improved to provide a largerclamping surface, an improved alignment with matingcomponents, and increased clearance to the lower shockmounting bracket.

W7000219

Radius SpringThe radius spring is crucial to the vehicle’s alignment.The radius spring has an improved bushing for increasedcomponent durability. The Volvo Air Suspension springuses a locating pin that precisely locates the radiusspring for an improved fit with the mating Z-spring andaxle seat. Precisely locating the radius spring helps toimprove the vehicles overall axle alignment.

W7000761

10


CrossbeamThe crossbeam (pedestal plate) has been greatly refinedto improve strength while reducing weight. The Volvo AirSuspension crossbeam uses only four mounting bolts(two on each end) for easy installation of the Z-spring.

W7000704

Crossbeam

Axle SeatThe axle seat defines the axle pinion inclination. It hasbeen refined to eliminate the extra spacers necessary inearlier designs. By eliminating the spacers, the Volvo AirSuspension axle seat forms a strong, secure joint be-tween the radius spring and the axle.

W7000727

Axle seat

Bottom PlateThe bottom axle plate is found underneath the axlehousing, and is held in place by U-bolts. It helps main-tain axle alignment with the springs in the suspensionand prevents movement of the axle. It can also be help-ful in keeping U-bolts properly aligned and secured.

W7000721

Bottom plate

Top PlateThe top plate (upper clip) is located at the top of the Z-spring and is clamped down by the U-bolts. It is helpfulin maintaining alignment of the U-bolts to secure andalign the Z-spring, radius spring, and axle seats. The topplate also helps maintain a secure surface for U-boltswhen torqued.

W7000712

Top plate

11


Air SpringThe air spring in the Volvo Air Suspension system is arolling-lobe, sleeve type with a composite piston. The airspring uses a single stud to attach to the crossbeam.

CAUTION

Do not mix the air springs of the Volvo Air Suspensionwith air springs of earlier suspensions. System failuremay result.

W7000225

Link RodThe Volvo Air Suspension uses a link rod that is factoryadjusted and set to accurately control the dimensions ofthe air springs, prevent inappropriate adjustments, andavoid unnecessary servicing.

W7000754

Leveling/Height ValveThe leveling valve was designed to simplify the chassisair suspension system. The quick-dump valve is nowcombined into the height control valve. This eliminatesone valve and the related plumbing.

The valve is located on the left side of the frame rail, ad-jacent to the fifth wheel.

The Volvo Air Suspension height valve incorporates anintegrated dump feature that eliminates the need for aseparate valve and allows the rear to be lowered to backunder a trailer.

W7000759

12


Shock Absorber Bracket, LowerThe lower shock absorber bracket on the Volvo Air Sus-pension has been redesigned to eliminate the need forleft-hand and right-hand versions.

W7000762

Shock Absorber Bracket, UpperThe upper shock absorber bracket has been redesignedto eliminate the need for left-hand and right-handversions.

W7000696

Torque RodThe torque rod is located on top of the axle housing. It ispositioned between the frame rail mounted bracket andthe axle housing mounted bracket. It helps maintain lat-eral alignment of the rear axle or axles for thesuspension.

W7000722

13


Pneumatic Switch PanelThe pneumatic switch panel can have as many as fouroptional equipment switches. They regulate air flow di-rectly to the equipment, including:

• Differential Lock• Wheel and Interaxle• Air Suspension Level• Fifth Wheel Slide

W7000714

TerminalSwitch SwitchFunction

A B C D

InteraxleDLO

To ClusterTelltale Lamp

+12V Supply Ground +12V Illumi-nationControl

Fifth WheelSlide


Not Used Ground +12V Illumi-nationControl

SuspensionDump


Not Used Ground +12V Illumi-nationControl

W3000574

W3000573

InterwheelDLO

N/A Not Used Ground +12V Illumi-nationControl

14


Dump Switch OperationTo “dump” air from the system, push the switch to theposition labeled “lower.”

To fill the system, push the switch to the position labeled“ride.”

Note: Lower the suspension when disconnecting thetrailer.

W7000700


15

Group 726 Volvo Air Suspension Troubleshooting

TroubleshootingTroubleshooting the Volvo Air Suspension

Problem Cause

U-joint angle incorrect

Improper phasing of drivelines

Axle inclination incorrect

Worn wear plate

Worn radius arm bushing

Improper ride height

Broken or defective Z-spring

Thrust alignment incorrect

Improper wheel run-out or balance

Broken or loose U-bolts

Excessive wheel bearing end play

Vibration

Mismatched wheels and tires

Broken or defective shock absorber

Defective leveling valve

Overloaded vehicle

Pressure regulator set too low

Wrong air spring

Improper ride height

Broken or defective spring

Bottoming Out

Low air pressure

Thrust alignment incorrect

Worn or defective torque rod bushing

Worn radius arm bushing

Broken or loose U-bolts

Broken or defective spring

Total wheel alignment incorrect

Tracking

Lateral alignment of axles incorrect


Ride height not set properly

Axle inclination incorrect

Overloaded vehicle

Ride Height Incorrect

Defective air spring

Defective manifold


Air leak or loose line

Defective pressure regulator

Low Air Pressure

Defective dump switch

17

Group 726 Volvo Air Suspension Service Procedures

Service ProceduresRide height has a direct relationship with driveline pinion angles. It is critical to main-tain all ride height specifications as recommended by Volvo Trucks North America.

Interaxle cancellation (equal forward and rear interaxle U-joint angles) is the key to re-duced driveline vibrations and increased component life. “Volvo Air Suspension RideHeight and Driveline Angle Check (Calculation) and Adjustment” page 20, describeshow to achieve interaxle cancellation by maintaining the proper ride height and pinionangles.

Guidelines for Working on theVolvo Air SuspensionTo ensure personal safety and to help avoid accidentaldamage to suspension components, follow these guide-lines any time work is performed on the Volvo AirSuspension.

1Chock the front wheels on vehicle andrelease the parking brakes.

Personal injury hazard. Never work under the vehicleunless the front wheels are securely chocked. Failureto chock the wheels can result in the vehicle rolling,which can cause serious injury or death to anyone un-der or near the vehicle.

2Dump (release) the suspension air.

Stay clear when suspension air is released. Chassismay drop quickly and can cause serious injury ordeath to anyone under the vehicle.

3When lifting the chassis to perform anyprocedure, always support the chassiswith adequate jack stands before be-ginning work on the air suspension.

Note: Never jack directly under thecrossbeam. The crossbeam is not de-signed to support vehicle weight.

Personal injury hazard. Never work under or around araised vehicle unless it is securely supported on jackstands of adequate rating. Failure to use adequatejack stands can result in the vehicle falling, which cancause serious injury or death to anyone under the ve-hicle.

19


4To ensure that the U-bolts holding therear suspension to the drive axle re-tain their clamp load, observe thefollowing practices:

a. Any time you work on the sus-pension, make sure you loosenboth sides of the suspension onan axle at the same time. It isdifficult to realign all parts with op-posite side of the axle restrictingmotion.

b. Whenever the U-bolts are loos-ened, always support the nose ofthe axle with an adequate jack.

Failure to properly support the nose of the axle mayresult in the axle falling, which can cause serious in-jury or death to anyone under the vehicle.

c. Whenever the U-bolts are loos-ened and/or the suspensioncomponents attached to the axleare being worked on, make surethat the locating features on eachcomponent is properly engagedso that the components are posi-tioned together properly.

d. Make sure that the pin in the ra-dius spring has not been pushedout of position. If the pin is cor-rectly set, make sure that the pinin placed in its proper position rel-ative to the axle seat and Z-springbefore clamping it with the U-bolts.

e. Always replace both U-bolts ata particular axle position. Thelonger of the two U-bolts is posi-tioned to the rear side of the axlehousing.

f. Before torquing the U-bolt nuts,position the suspension at approx-imately the normal ride height andmake sure the bolts holding thecrossbeam (pedestal plate) to theZ-spring are loosened. This willhelp provide proper alignment forthe Z-springs.

g. Always “snug-up” the U-boltnuts all over first before torquing,using a handheld clicker-styletorque wrench.

5After work has been performed on theair suspension, vehicle realignmentmay be required. Refer to proper ser-vice information.

Volvo Air Suspension RideHeight and Driveline AngleCheck (Calculation) and Ad-justment

WARNING

The Volvo Air Suspension is set at the factory. Chang-ing the ride height will affect the driveshaft angles andmay cause driveline vibration and/or shorten compo-nent life. Ride height adjustments must beperformed in accordance with all service manualprocedures.

Special tools: J–42189Other special equipment: J38460–A,J38460–25

20


Air Suspension Ride HeightCheck (Calculation)1

W7000741

1 Leveling valve2 Ride height3 Axle center line4 Crossbeam

Before you can accurately calculatethe ride height, prepare the vehicle us-ing these steps:

• Measurements must be per-formed on an unloaded vehicle.

• Park the vehicle on a level sur-face.

• The steer and rear drive axle tiresmust be at normal operating pres-sure.

• Free and center all suspensionjoints by slowly moving the vehicleback and forth twice without usingthe brake. When coming to acomplete stop, make sure thebrakes (parking and service) arereleased.

• Front wheels must be pointedstraight ahead.

2Chock the front wheels on the vehicle.


3Dump (release) the suspension air(see “Dump Switch Operation” page15).


Start the engine and fill the suspen-sion with air. Turn off the engine.

4

W7000755

The ride height is the distance fromthe axle centerline to the bottom of theframe rail. The ride height must bewithin the following specifications:

• Low frame [outside rail height di-mension approx. 266 mm (10.5in.)]: 196–216 mm (7.75–8.5 in.)

• High frame [outside rail height di-mension approx. 300 mm (11.75in.)]: 179–199 mm (7.0–7.75 in.)

To accurately measure ride height:

a. Measure from the ground to thebottom of the frame rail (1).b. Locate the axle centerline (thecenter hole on the end of the hubworks best) using a steel rule oran appropriate tool (2). Measurefrom the ground to the axle cen-terline (3).c. Calculate the difference be-tween (1) and (3). The differenceis the ride height (4).d. Ride height should fall withinspecifications for low- or high-railchassis (see above).

21


5Record the measurement for calcula-tion (refer to “Volvo Air Suspension —Calculation Form” page 51). If themeasurement is not within the speci-fied range, it must be corrected beforeproceeding. If the ride height is not inspecification, check for the following:

• Excessively worn wear plates(pads).

Note: Wear plates (pads) must bereplaced in pairs (left and right onsame axle); see “Wear Plate(Pad) Replacement” page 40.

• Damaged spring hanger framebracket.

• Damaged air spring, Z-spring,and/or radius spring.

• Damaged link rod.

• Faulty leveling valve.

Replace the components as neces-sary, then adjust the suspension rideheight (see “Volvo Air SuspensionRide Height Adjustment” page 28).

6Remeasure the ride height using steps4a-d of this procedure. Repeat as nec-essary until the measurement is withinspecifications.

7Proceed to “Interaxle U-joint AngleCancellation Check (Calculation)”page 22.

Interaxle U-joint Angle Cancella-tion Check (Calculation)1The steps from “Air Suspension RideHeight Check (Calculation)” page 21,must be performed before continuingwith this procedure.

Note: All angle measurements are rel-ative to level ground.

2

W7000742

W7000252

Measure the forward axle angle (A)using an inclinometer or recommendedtool. Record the measurement forcalculation (refer to “Volvo Air Suspen-sion — Calculation Form” page 51).

Note: Wipe surface clean of dirt anddebris before taking measurement.

22


3

W7000756

Measure the interaxle shaft angle (B)using the recommended tooling.Record the measurement for calcula-tion (refer to “Volvo Air Suspension —Calculation Form” page 51).


4Calculate : B – A = DThe interaxle angle minus the forwardaxle angle will give the value (D) (referto “Volvo Air Suspension — Calcula-tion Form” page 51).

5

W7000742

W7000253

Measure the rear axle angle (C) usingthe recommended tooling. Record themeasurement for calculation (refer to“Volvo Air Suspension — CalculationForm” page 51).


6Calculate: C – B = EThe rear axle angle minus the inter-axle angle will give the value (E).Record the measurement for calcula-tion (refer to “Volvo Air Suspension —Calculation Form” page 51).

23


7Calculate: D – E = FRecord the measurement for calcula-tion (refer to “Volvo Air Suspension —Calculation Form” page 51).

Compare the value of angle (F) withthe following guidelines:

If (F) is less than -1.5, lower theride height.

If (F) is between -1.5 and +1.5, noadjustment is necessary.

If (F) is greater than +1.5, raisethe ride height.

For procedures on lowering or raisingride height, refer to “Volvo Air Suspen-sion Ride Height Adjustment” page 28.

8Proceed to “Forward Axle Pinion An-gle to Frame Check” page 25.

24


Forward Axle Pinion Angle toFrame Check1

W7000757

Place an inclinometer or recom-mended tool on top of the frame.“Zero-out” inclinometer or recom-mended tool.

2

W7000743

W7000252

Measure the forward axle angle (P),using the “zero’d out” inclinometer orrecommended tool.

3The angle (P) measurement must bewithin the specified range, as shown inthe following table:

Forward Axle Angle Relative toFrame (P)

Axle Model Specification (indegrees)

Tandem, 6x4 2.5 +0/-1

Single, 4x2 3.5 ± 1

If angle (P) is outside the specifica-tions, it must be corrected. Check forthe following:

• Excessively worn wear plates(pads).

Note: Wear plates (pads) must bereplaced in pairs (left and right onsame axle); see “Wear Plate(Pad) Replacement” page 40.

• Damaged spring hanger framebracket.

• Damaged air spring, Z-spring,and/or radius spring.

• Damaged link rod.

• Broken/loose U-bolts.

• Faulty leveling valve.

Replace the components as neces-sary, then adjust the suspension rideheight (see “Volvo Air SuspensionRide Height Adjustment” page 28).

4Repeat all steps in “Air SuspensionRide Height Check (Calculation)” page21, “Interaxle U-joint Angle Cancella-tion Check (Calculation)” page 22, and“Forward Axle Pinion Angle to FrameCheck” page 25.

Note: If, after the second attempt, theaxle pinion angles are still not withinspecification, perform the “U-boltTorque Procedure” page 26, as a lastattempt to correct the axle pinion an-gles.

25


U-bolt Torque ProcedureLoosening and re-torquing the suspension U-bolts in aparticular sequence can influence the axle pinion angle.Both U-bolts on the left and right side on the same axlemust be loosened and re-torqued. See “Guidelines forWorking on the Volvo Air Suspension” page 19, beforeperforming this procedure.

Method 1 (preferred)1

W7000752

Support the nose of the axle with anadequate jack.

Failure to properly support the nose of the axle mayresult in the axle rolling forward.

Personal injury hazard! Never work under or arounda raised vehicle unless it is securely supported onjack stands of adequate rating. Failure to use ade-quate jack stands can result in the vehicle falling,which can cause serious injury or death to anyone un-der the vehicle.

2Loosen the U-bolts enough to allowthe bottom plate to be slightly freefrom the axle housing. Lower the jackslightly, approximately 10–12 mm(0.38–0.50 in.).

3“Snug-up” the U-bolt nuts so that thereis no movement in the bottom plate.

4

W7000750

Hand-torque the U-bolts to 500 ± 75Nm (369 ± 55 ft-lb) for M20, or 575 ±50 Nm (424 ± 37 ft-lb) for M22.

Note: Use the “crossover method”(see pattern above) to evenly tightenthe U-bolt nuts. Torque nuts in approx-imately 100 Nm (75 ft-lb) incrementsuntil full torque is obtained.

M20:500 ± 75 Nm(369 ± 55 ft-lb)M22:575 ± 50 Nm(424 ± 37 ft-lb)

5Road-test the vehicle to seat compo-nents, then re-torque the U-bolt nuts.

6Re-perform the procedure: “Volvo AirSuspension Ride Height and DrivelineAngle Check (Calculation) and Adjust-ment” page 20. If axle pinion anglesare still outside the specifications, pro-ceed with Method 2.

26


Method 21

W7000752



Personal injury hazard! Never work under or arounda raised vehicle unless it is securely supported onjack stands of adequate rating. Failure to use ade-quate jack stands can result in the vehicle falling,which can cause serious injury or death to anyone un-der the vehicle.

2Loosen the U-bolts enough to allowthe bottom plate to be slightly freefrom the axle housing. Lower the jackslightly, approximately 10–12 mm(0.38–0.50 in.).

3“Snug-up” the U-bolt nuts so that thereis no movement in the bottom plate.

4Hand-torque the U-bolts to 500 ± 75Nm (369 ± 55 ft-lb) for M20, or 575 ±50 Nm (424 ± 37 ft-lb) for M22.

Note: Torquing one U-bolt before theother can influence the axle pinion an-gle.Torquing the nuts on the U-bolt on therear side of the axle housing (left andright) first can decrease the axle pin-ion angle.Torquing the nuts on the U-bolt on thefront side of the axle housing (left andright) first can increase the axle pinionangle.

M20:500 ± 75 Nm(369 ± 55 ft-lb)M22:575 ± 50 Nm(424 ± 37 ft-lb)

5Road-test the vehicle to seat compo-nents, then re-torque the U-bolt nuts.

6Re-perform the procedure: “Volvo AirSuspension Ride Height and DrivelineAngle Check (Calculation) and Adjust-ment” page 20.

27


Volvo Air Suspension RideHeight Adjustment1The suspension ride height is raisedor lowered by adjusting the link rodlength.

Note: If the vehicle is equipped with anon-adjustable (fixed length) rod, itmust be replaced with an adjustablelink rod before performing this proce-dure. See “Link Rod Replacement”page 31.

2

W7000710

1 Clamp2 Washer

Remove the clamp from the lower endof the link rod. Remove the nut anddisconnect the lower end of the link rodfrom the crossbeam (pedestal plate).The upper end of the link rod shouldremain mounted to the leveling valvearm during the adjustment procedure.

3Install a new clamp on the rubbermount on the lower end of the link rod.

Note: If using a permanent “crimp”style clamp, you must first remove therubber mount from the link rod beforeinstalling the clamp.

4

W7000746

A - RaiseB - NeutralC - Lower

Raising ride height:Raise the ride height by holding theleveling valve arm upwards until theride height is within specifications, asfollows:



Use caution when moving the leveling valve armdown. This will release the suspension air and thechassis may drop quickly, possibly causing serious in-jury or death to anyone under the vehicle.

ORLowering ride height:Lower the ride height by holding theleveling valve arm down until the rideheight is within specifications, as fol-lows:



28


5

W7000748

Return the leveling valve arm to theneutral position. Place the short sideof a 5/32 in. Allen wrench through thehole (1) on the leveling valve arm andinto the valve. This locks the arm inthe neutral position.

Note: If the leveling valve arm is notkept in the neutral position, the rideheight may move out of the specifiedrange.

6Adjust the position of the lower rubbermount on the link rod so that the lowermounting stud is aligned with the holein the crossbeam (pedestal plate).

7Reinstall the lower mounting stud ofthe link rod to the crossbeam. Notethe position of the washer. Torque to10 ± 1.5 Nm (7 ± 1 ft-lb).

Note: Do not crimp or tighten theclamp at the lower end of the link rodat this time.

10 ± 1.5 Nm(7 ± 1 ft-lb)

8Remove the Allen wrench from theleveling valve.

CAUTION

Failure to remove the Allen wrench will damage theleveling valve and/or link rod.


Stay clear when suspension air is released. Chassismay drop quickly possibly causing serious injury toanyone under the vehicle.

10Crank the truck to build up air pres-sure to check the ride height (see “AirSuspension Ride Height Check (Calcu-lation)” page 21). The ride height mustbe within specifications, as follows:

Low frame [outside rail height di-mension approx. 266 mm (10.5in.)]: 196–216 mm (7.75–8.5 in.)

High frame [outside rail height di-mension approx. 300 mm (11.75in.)]: 179–199 mm (7.0–7.75 in.)

11Perform the “Interaxle U-joint AngleCancellation Check (Calculation)”page 22), and the “Forward Axle Pin-ion Angle to Frame Check” page 25

12Crimp or tighten clamp at the lowerend of the link rod.

29


Volvo Air Suspension Compo-nent ReplacementNote: Before replacing any component or performingany other work on the Volvo Air Suspension, be sureto read “Guidelines for Working on the Volvo AirSuspension” page 19.

Leveling Valve Replacement

CAUTION

Do not try to adjust the leveling valve. Do not take theleveling valve apart. Do not lengthen or shorten thehandle on the valve.

Removal

1Chock the front wheels on vehicle andrelease the parking brakes.




3Remove the rod from the levelingvalve arm.

4

W7000709

Remove the bolts from the frame hold-ing the valve mounting bracket inplace.

5Note the air line positions and orienta-tion to the fittings in the valve.Disconnect the air lines, and removethe valve.

6Swap fittings (or position new fittings)to the replacement valve.

7Swap bracket from former valve to re-placement valve. Torque to 10 ± 1.5Nm (7 ± 1 ft-lb).

10 ± 1.5 Nm(7 ± 1 ft-lb)

30


Installation

8Lay the valve in the frame and installthe air lines.

9Install the bolts through the frame andthe valve bracket. Torque bolts to 60 ±10 Nm (44 ± 7 ft-lb).

60 ± 10 Nm(44 ± 7 ft-lb)

10

W7000713

Connect the link rod onto the arm.Torque the rod to 10 ± 1.5 Nm (7 ± 1ft-lb).

10 ± 1.5 Nm(7 ± 1 ft-lb)

11When completed, crank the truck tobuild up air pressure to check the rideheight (see “Air Suspension RideHeight Check (Calculation)” page 21).

The ride height must be within the fol-lowing specifications:



See “Volvo Air Suspension RideHeight Adjustment” page 28.

Link Rod ReplacementRemoval



2Unbolt link rod from leveling valve armand crossbeam (pedestal). Removefrom vehicle.

Installation

3Pre-set the length of the replacementlink rod to approximately 505 mm(19.88 in.).

Note: Do not crimp or tighten theclamp at the lower end of the link rodat this time.

31


4

W7000745

1 Washer

W7000710

1 Clamp2 Washer

Install link rod. Note position ofwasher. Torque both nuts to 10 ± 1.5Nm (7 ± 1 ft-lb).

Note: Mount in same hole in thecrossbeam (pedestal) as the originallink rod. Do not crimp or tighten clampat lower end of the link rod at this time.

10 ± 1.5 Nm(7 ± 1 ft-lb)

5When completed, crank the truck tobuild up air pressure to check the rideheight (see “Air Suspension RideHeight Check (Calculation)” page 21).

The ride height must be within the fol-lowing specifications:



See “Volvo Air Suspension RideHeight Adjustment” page 28.

6Crimp or tighten clamp at the lowerend of the link rod.

32


Crossbeam (Pedestal Plate)ReplacementRemoval

1Raise the rear suspension and supportthe frame with jack stands, maintainingthe approximate ride height. Dump (re-lease) the suspension air to relievepressure off the air springs.

Stay clear when suspension air is released. Chassismay drop quickly, possibly causing serious injury toanyone under the vehicle.

2Remove the nuts that hold the airbags to the crossbeam (pedestalplate). Push the air springs out of thecrossbeam and forward.

3

W7000707

Remove the nuts and bolts that holdthe crossbeam to the Z-springs andremove the crossbeam.

Installation

4Install the crossbeam to the Z-springwith the nuts and bolts. Torque thebolts to 105 ± 20 Nm (77 ± 15 ft-lb).

105 ± 20 Nm(77 ± 15 ft-lb)

5Install the air springs back onto thecrossbeam and torque the nuts to 50± 10 Nm (37 ± 7.5 ft-lb).

CAUTION

Over-torque will damage the air spring.

50 ± 10 Nm(37 ± 7.5 ft-lb)

6When completed, jack the rear of thetruck up, remove the jack stands andlower the vehicle. Crank the truck tobuild air pressure to raise the air sus-pension.

33


Z-Spring ReplacementRemoval

1Remove isolator (spring roller) fromspring hanger (frame) bracket. This islocated under “hook end” of Z-spring.

2

W7000718

Chock wheels on vehicle. Jack up ve-hicle and place jack stands underframe rails. Secure jack stands andlower vehicle.

Note: Follow the “Guidelines forWorking on the Volvo Air Suspension”page 19.

Personal injury hazard. Never work under the vehicleunless the front wheels are securely chocked. Failureto chock the wheels can result in the vehicle rolling,which can cause serious injury or death to anyone un-der the vehicle.

3Remove wheels and tires on axle (oraxles) to be worked on.

4

W7000763

W7000752

Jack up vehicle and place jack standsunder axle(s) being worked on. Whilelowering vehicle onto jack stands, sup-port the nose of the axle with a bottlejack.


Personal injury hazard! Never work under or arounda raised vehicle unless it is securely supported onjack stands of adequate rating. Failure to use ade-quate jack stands can result in the vehicle fallingand/or rolling, which can cause serious injury or deathto anyone under the vehicle.

34


5

W7000715

Remove nuts from U-bolts, then re-move bottom plate, U-bolts, and top(clip) plate. Leave lower shock bracketattached to shock absorber, but movebracket clear of work area.

6Remove bolts from crossbeam(pedestal plate).

7Remove Z-spring.

Installation

8Install Z-spring into place.

9Install bolts to crossbeam. Leaveloose; do not torque at this time.

10Install top (clip) plate, U-bolts, and bot-tom plate. Reposition lower shockbracket. “Snug up” U-bolt nuts, but donot torque at this time.

11Raise vehicle and remove jack standssupporting the axle(s).

12Install wheels and tires. Torque wheeland tire nuts to 645 ± 35 Nm (475 ±25 ft-lb.)

645 ± 35 Nm(475 ± 25 ft-lb)

13Raise vehicle and temporarily removeremaining jack stands supporting theframe rails. Lower the vehicle to theground.

14Crank the vehicle to build air pressureto raise the air suspension.

15Reinstall the isolator (spring roller)with retaining pin and split pin.

16Support the frame with jack stands(maintaining the approximate normalride height). Deflate the air springs torelieve pressure off the Z-spring.

17Center the Z-spring within the springhanger (frame) bracket.

Note: It may be necessary to tem-porarily position a shim between theleft side of the spring and the leg ofthe spring hanger (frame) bracket tokeep the Z-spring centered during theU-bolt nut torque procedure.

35


18Torque U-bolt nuts to 500 ± 75 Nm(369 ± 55 ft-lb) for M20, or to 575 ± 50Nm (424 ± 37 ft-lb) for M22.

Note: To ensure proper torque, referto “U-bolt Torque Procedure” page 26.

M20:500 ± 75 Nm(369 ± 55 ft-lb)M22:575 ± 50 Nm(424 ± 37 ft-lb)

19Torque nuts for crossbeam mountingbolts to 105 ± 20 Nm (77 ± 15 ft-lb).

105 ± 20 Nm(77 ± 15 ft-lb)

20Raise the vehicle and remove jackstands supporting frame rails.

21Crank the truck to build air pressure toraise the air suspension. Perform theprocedures for “Volvo Air SuspensionRide Height and Driveline AngleCheck (Calculation) and Adjustment”page 20.

Note: Vehicle realignment may be re-quired. See “Guidelines for Workingon the Volvo Air Suspension” page 19.

Radius Spring ReplacementRemoval

1

W7000752

Chock front wheels on vehicle. Jackup vehicle and place jack stands un-der axle(s) being worked on. Lowervehicle onto jack stands to support thenose of the axle.



2Remove nuts from U-bolts on axle tobe worked on.


36


3

W7000725

Raise vehicle from under the rear ofthe Z-spring at the crossbeam(pedestal plate) just enough to sepa-rate the Z-spring from the radiusspring.

4

W7000720

Remove the two (2) bolts from thelower part of the spring anchor, thenremove the radius spring.

Installation

5Install radius spring into place and in-stall the two (2) bolts. Torque to 275 ±45 Nm (203 ± 33 ft-lb).

275 ± 45 Nm(203 ± 33 ft-lb)

6Lower vehicle, making certain that Z-spring and radius spring are properlyaligned.

7Install U-bolt nuts, making certain thataxle seats are properly aligned withthe Z-spring and radius spring. “Snugup” bolts, but do not torque at this time.

8Loosen (but do not remove) the boltsfor the crossbeam (pedestal plate) toZ-spring mounting.

9Make sure the rear suspension is ap-proximately at normal ride height (airsprings inflated).

10Support the frame with jack stands(maintaining the approximate normalride height). Deflate the air springs torelieve pressure off the Z-spring.




Note: To ensure proper, refer to“U-bolt Torque Procedure” page 26.

M20:500 ± 75 Nm(369 ± 55 ft-lb)M22:575 ± 50 Nm(424 ± 37 ft-lb)

13Torque nuts for crossbeam mountingbolts to 105 ± 20 Nm (77 ± 15 ft-lb).

105 ± 20 Nm(77 ± 15 ft-lb)


15Crank the truck to build air pressure toraise the air suspension.

Note: Vehicle realignment may be re-quired. See “Guidelines for Workingon the Volvo Air Suspension” page 19.

37


Torque Rod and Frame BracketReplacementRemoval

1Remove any wires or air line clippingsfrom torque rod.

2

W7000716

Remove the two (2) bolts throughtorque rod at frame rail side bracket.

3Remove the two (2) bolts throughtorque rod at axle housing bracket andremove the torque rod.

4Remove the four (4) fasteners to thetorque rod bracket at the frame railand remove the bracket.

Note: These may be Huck-style fas-teners, which require additional effortfor removal.

WARNING

Heating the suspension components and frame railmay weaken them. Hot surfaces can also cause seri-ous burns.

Installation

5Install four (4) bolts to torque rodbracket at frame rail.

Note: Use only approved fasteners.

6Install two (2) bolts through torque rodat axle housing bracket.

7Install two (2) bolts through torque rodat frame rail side bracket.

8Torque the bolts to torque rod andtorque rod bracket to 320 ± 50 Nm(236 ± 37 ft-lb).

320 ± 50 Nm(236 ± 37 ft-lb)

9Re-attach any wires or air line clip-pings to the torque rod.

38


Spring Hanger (Frame) BracketReplacementRemoval

1

W7000720

Remove the retaining pin and isolator(spring roller) from spring hanger(frame) bracket (located under “hookend” of Z-spring).


2

W7000718

Place jack stands on each side oftruck and deflate air bags to relievepressure off of the Z-spring.

3Remove the nuts and bolts from theradius spring.

4Remove nuts from the bolts on thespring hanger.

Note: These may be Huck-style fas-teners, requiring additional effort forremoval.

WARNING


5Raise the rear of the truck to relievepressure from the spring hanger bolts.

39


6

W7000720

Remove spring hanger bolts in frontand behind the bracket.

7Remove hanger.

8Remove the split pin and retaining pinholding the wear plate (pad) into thespring hanger (frame) bracket. Re-move the wear plate.

Note: We recommend replacing wearplates (pads). They should be re-placed in pairs (left and right) on thesame axle. See “Wear Plate (Pad)Replacement” page 41.

Installation

9Install the wear plate (pad), add retain-ing pin and replacement split pin in thespring hanger (frame) bracket.

Note: New plates (pads) should be in-stalled. They should be replaced inpairs (left and right) on the same axle.See “Wear Plate (Pad) Replacement”page 41.

10Work the spring hanger bracket backonto the Z-spring.

11Install all bolts to reattach the springhanger and any other bolts that wereremoved to get to spring hanger.Torque spring hanger bolts to 320 ±50 Nm (236 ± 37 ft-lb).


320 ± 50 Nm(236 ± 37 ft-lb)

12Install bolts for radius spring. Torqueradius spring bolts to 275 ± 45 Nm(203 ± 33 ft-lb).

275 ± 45 Nm(203 ± 33 ft-lb)

13Install retaining pin and isolator (springroller) in spring hanger (frame)bracket, under Z-spring.

14Raise the vehicle and remove jackstands supporting the frame rails.Lower the vehicle to the ground.


16Ride height and pinion angle may re-quire adjustment. See “Volvo AirSuspension Ride Height and DrivelineAngle Check (Calculation) and Adjust-ment” page 20.

Note: Vehicle wheel realignment maybe required. See “Guidelines forWorking on the Volvo Air Suspension”page 19.

40


Wear Plate (Pad) ReplacementRemoval

1

W7000720

Remove the retaining pin and isolator(spring roller) from spring hanger(frame) bracket (located under “hookend” of Z-spring).


Note: It is strongly recommended thatthe wear plates (pads) be replaced inpairs (left and right side) on the sameaxle.

2Chock front wheels on vehicle.





4

W7000725

Jack the vehicle from under the rear ofthe Z-spring at the crossbeam(pedestal plate) mounting until there issufficient gap between the wear plateand Z-spring to remove the wear plate.

Note: Jacking both the left and rightsides simultaneously will help obtain asufficient gap. Also, lifting (and prop-erly supporting) the rear of the chassismay increase the size of the gap.

5Remove the split pin and the retainingpin holding the wear plate into thespring hanger (frame) bracket.

6Pry out the old wear plate.

41


Installation

7Install the replacement wear plate intothe spring hanger (frame) bracket.

Note: The thick end of the wear plateis always positioned to the rear of thevehicle.

8Install the retaining pin and a replace-ment split pin into the spring hanger(frame) bracket to hold the installedwear plate.

9Remove the supports and lower thevehicle to the ground.

10Crank truck to build air pressure toraise the air suspension.

11Install the isolator (spring roller), re-taining pin, and a replacement split pinin the spring hanger (frame) bracket,under the Z-spring.

12Ride height and axle pinion angle mayrequire adjustment. See “Volvo AirSuspension Ride Height and DrivelineAngle Check (Calculation) and Adjust-ment” page 20.

Upper Shock Absorber BracketRemoval and InstallationRemoval

1

W7000744

Remove upper shock mounting bolt.Remove shock and position out of thework area.

2Remove frame fasteners from uppershock bracket.

Note: These may be Huck-style fas-teners, requiring additional effort forremoval.

WARNING


3Remove upper shock bracket.

42


Installation

4Install the shock bracket. Torque fas-teners to 320 ± 50 Nm (236 ± 37 ft-lb).


320 ± 50 Nm(236 ± 37 ft-lb)

5Install shock, bushings, and uppershock mounting bolt. Torque bolt to 60± 10 Nm (44 ± 7 ft-lb).

Note: When replacing shocks, useonly Volvo-approved components(shocks and bushings).

60 ± 10 Nm(44 ± 7 ft-lb)

Lower Shock Absorber BracketRemoval and InstallationRemoval

1Chock front wheels on vehicle and re-move nuts from U-bolts on axle to beworked on.



2

W7000752




43


3

W7000744

Remove nuts from rear U-bolt. Loosenbolts from front U-bolt, but do not re-move.

4Remove lower shock bracket from U-bolt.

5Remove lower shock mounting boltand remove lower shock bracket.

Installation

6Install shock, bushings, and lowershock mounting bolt. Torque bolt to 60± 10 Nm (44 ± 7 ft-lb).


60 ± 10 Nm(44 ± 7 ft-lb)

7Install lower shock bracket. Install U-bolts and “snug up.”

8Torque fasteners to 500 ± 75 Nm (369± 55 ft-lb) for M20, or 575 ± 50 Nm(424 ± 37 ft-lb) for M22.

Note: To ensure proper torque, referto “U-bolt Torque Procedure” page 26.

M20:500 ± 75 Nm(369 ± 55 ft-lb)M22:575 ± 50 Nm(424 ± 37 ft-lb)

Shock Absorber Removal andInstallationRemoval

1

W7000744

Remove lower shock mounting bolt.


2Remove upper shock mounting boltand remove shock.

Installation

3Install shock and bushings. Torquebolts to 60 ± 10 Nm (44 ± 7 ft-lb).


60 ± 10 Nm(44 ± 7 ft-lb)

44


Rear Axle Top Plate/BottomPlate Removal and InstallationRemoval

1Chock front wheels on vehicle.



2

W7000752




3Remove nuts from the U-bolts, thenremove the bottom plate and U-bolts.Leave lower shock bracket attached toshock absorber, but position bracketclear of the work area.

45


4

W7000747

Remove the top plate.

Installation

5Install the top plate.

Note: Make sure the alignment pin onthe bottom of the top plate is engagedinto the pocket on the top surface ofthe Z-spring.

6Install the U-bolts.

Note: The longer U-bolt is positionedto the rear side of the axle housing.

7Install the bottom plate.

Note: Install with the arrow (locatedon the bottom of the plate) pointing to-ward the front of the truck.

8Reposition the lower shock bracket onthe U-bolt.

9“Snug up” the U-bolt nuts, but do nottorque.

10Loosen the mounting bolts for thecrossbeam (pedestal plate) to the Z-spring.

11Remove the jack stands and lower thevehicle to the ground.


13Support the frame (maintaining the ap-proximate normal ride height). Deflatethe air springs to relieve pressure offof the Z-springs.




Note: To ensure proper torque, referto the “U-bolt Torque Procedure” page26.

M20:500 ± 75 Nm(369 ± 55 ft-lb)M22:575 ± 50 Nm(424 ± 37 ft-lb)

16Tighten the nuts for crossbeam mount-ing bolts to the Z-spring. Torque to105 ± 20 Nm (77 ± 15 ft-lb).

105 ± 20 Nm(77 ± 15 ft-lb)



Note: Ride height and pinion anglemay require adjustment. See “VolvoAir Suspension Ride Height and Drive-line Angle Check (Calculation) andAdjustment” page 20.

46


Air Spring Removal and Instal-lationRemoval

1Support the frame (maintaining the ap-proximate normal ride height). Deflateair springs.

2Remove air lines from air springs.

Pneumatic components store compressed air and canseparate violently during disassembly or removal. Be-fore servicing any part of the pneumatic (air) system,completely release the air pressure. Failure to do socan result in serious personal injury or death.

3

W7000719

Remove the 2 upper frame bolts andbottom nut.

4Remove the air spring from the chas-sis.

5Remove the fitting from the air spring.

Installation

6Install the fitting in the air spring.

7Install the air spring back onto theframe and crossbeam (pedestal plate).

8Torque frame mounting bolts to 320 ±50 Nm (236 ± 37 ft-lb).

320 ± 50 Nm(236 ± 37 ft-lb)

9Torque lower nut to 50 ± 10 Nm (37 ±7.5 ft-lb).

CAUTION

Over-torque will damage air spring.

50 ± 10 Nm(37 ± 7.5 ft-lb)

10Install the air lines into the air springs.

11Crank truck to build pressure to inflatethe air suspension. Remove supportsfrom frame.

12Check ride height (see “Volvo AirSuspension Ride Height and DrivelineAngle Check (Calculation) and Adjust-ment” page 20).

47


Pneumatic switch replacementNote: Make certain the vehicle ignition is OFF beforebeginning this procedure.

Removal1

W3000649

Remove the ashtray from the ashtrayhousing. Remove the 2 screws fromthe ashtray housing, and remove thehousing.

2Once the ashtray housing is removed,the air switch panel can be removedfrom the dash. Pull the air switchpanel away from the dash and to theleft to clear the tip inserts.

3

W3000656

Disconnect the 2 terminal connectorsfrom the cigar lighter and the electricalLED connections on the switch beingreplaced.

4

Never disconnect an air system component unless allsystem pressure has been depleted. Failure to de-plete system pressure before disconnecting hoses orcomponents may result in them separating violentlyand causing serious bodily injury.

Drain air pressure from vehicle sys-tem. Mark each air line to keep correctarrangement.

5

W7000706

Disconnect air lines at switch being re-placed by pushing in on the ring andair line using the air line release tool(J-42189), then pulling the air line out.

J-42189

6

W3000658

To remove switch, insert a no. 1 flat tipscrewdriver into back of switch at topand bottom to release locking tabs.Push switch out of the panel.

Installation1Install new air switch into the panel,pushing the switch into the panel untilit locks. Push back on the switch tomake certain it is locked in the panel.

48


2Connect air lines to the switch, makingsure they are installed in the correctposition. Be sure to insert airline toline indicated.

3Connect electrical LED connections onswitch, and both cigar lighter connec-tions.

4Align and install switch panel in dash.

5Install ashtray housing with the 2mounting screws. Torque screws to0.4 ± 0.1 Nm (3.5 ± 1 in-lb).

0.4 ± 0.1 Nm(3.5 ± 1 in-lb)

6Place ashtray in housing.

49

Group 726 Volvo Air Suspension System Check

System Check


W7000753

51


Volvo Air Suspension Ride Height and Driveline Angle Check FlowDiagram

W7000749

1 See “Volvo Air Suspension Ride Height and Driveline Angle Check (Calculation) and Adjustment” page 202 See “Interaxle U-joint Angle Cancellation Check (Calculation)” page 223 See “Volvo Air Suspension Ride Height Adjustment” page 284 See “Volvo Air Suspension Component Replacement” page 305 See “Forward Axle Pinion Angle to Frame Check” page 256 See “U-bolt Torque Procedure” page 26

52


Volvo Air Suspension — Calculation FormUse this form to record the measurements for calculating ride height and checking pin-ion angles (all angle measures are in degrees).

W7000743

MEASUREMENTSANGLEINITIAL FINAL

1) MEASURE THE RIDE HEIGHT:Ride Height must be within specifications for the following frame types:

Low - outside rail height dimension approx. 266 mm (10.5 in.): 196 - 216 mm (7.75 - 8.5 in.)

High - outside rail height dimension approx. 300 mm (11.75 in.): 179 - 199 mm (7.0 - 7.75 in.)

If ride height is not within specification, it must be corrected before continuing.

2) MEASURE FORWARD AXLE ANGLE A(Relative to the ground)

3) MEASURE THE INTERAXLE SHAFT B(Relative to the ground)

4) CALCULATE: B - A = DThe difference between B and A is value "D"

5) MEASURE THE REAR AXLE ANGLE CRelative to the ground

6) CALCULATE: C - B = EThe difference between C and B is value "E"

7) CALCULATE: D - E = ± F

ACTION: LOWER RIDE HEIGHT No Adjustment RAISE RIDE HEIGHT

Note: The Air Suspension ride height cannot fall outside the specified tolerance.If the adjustment for angle (F) requires that the air suspension ride height be adjustedoutside the specified range, see “Troubleshooting the Volvo Air Suspension” page 17.

SPECIFICATIONS

Tandem, 6x4 2.5 +0/-1MEASURE FORWARD AXLE

ANGLE (RELATIVE TO FRAME)Single, 4x2 3.5±1

P

Note: If angle (P) is not within tolerance, see “Troubleshooting the Volvo Air Suspen-sion” page 17.

53

Operation Numbers

Volvo Trucks North America, Inc.P.O. Box 26115, Greensboro, NC 27402-6115

Volvo Trucks Canada, Ltd.6490 Vipond Drive, Mississauga, Ontario L5T 1W8

http://www.volvotrucks.volvo.com

PV776-TSP27725/1 (2000) 11.97 © Volvo Trucks North America, Inc., 97

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