SERVICE PROCEDURE
G-12524
OCTOBER 2012
SUBJECT:

SAFETY RECALL
Piston spring brakes on certain DuraStar®,
ProStar®, TranStar®, and WorkStar® models built
29 November, 2010 thru 2 April, 2012 with feature
code 04EVP.

DEFECT DESCRIPTION
The piston in the spring brake chamber may in certain cases, cause internal air
leakage in the chamber. An internal leak past the spring piston could result in the
parking brake not fully releasing in some cases which could result in partial to full
brake application. An unexpected application of the parking brake may contribute
to a vehicle crash which may result in property damage, personal injury, or
death.

MODELS INVOLVED
This Safety Recall involves certain DuraStar®, ProStar®, TranStar®, and
WorkStar® models built 29 November, 2010 thru 2 April, 2012 with feature code
04EVP piston spring brakes.

PARTS INFORMATION
Part Number

Part Description

Quantity

ZAJMJS3024ET951

Chamber; combination with welded yoke.

2

SERVICE PROCEDURE
WARNING! PARK VEHICLE ON HARD FLAT SURFACE, TURN THE ENGINE
OFF, SET THE PARKING BRAKE AND BLOCK THE WHEELS TO PREVENT
THE VEHICLE FROM MOVING IN BOTH DIRECTIONS. FAILURE TO DO SO
MAY RESULT IN PROPERTY DAMAGE, PERSONAL INJURY AND/OR
DEATH.

VEHICLE RECALL G – 12524

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WARNING! IF THE VEHICLE MUST BE RAISED, DO NOT WORK UNDER THE
VEHICLE SUPPORTED ONLY BY JACKS. JACKS CAN SLIP OR FALL OVER,
POTENTIALLY RESULTING IN PROPERTY DAMAGE, PERSONAL INJURY
AND/OR DEATH.
WARNING! ALWAYS WEAR SAFE EYE PROTECTION WHEN PERFORMING
VEHICLE MAINTENANCE. FAILURE TO DO SO MAY RESULT IN SERIOUS
EYE INJURY.
WARNING! ALLOW COMPONENTS IN ENGINE COMPARTMENT TO COOL
BEFORE SERVICING ENGINE OR VEHICLE. FAILURE TO DO SO MAY
RESULT IN PROPERTY DAMAGE, PERSONAL INJURY AND/OR DEATH.
WARNING! KEEP FLAMES OR SPARKS AWAY FROM VEHICLE AND DO
NOT SMOKE WHILE SERVICING THE VEHICLE’S BATTERIES. BATTERIES
EXPEL EXPLOSIVE GASES. FAILURE TO DO SO MAY RESULT IN
PROPERTY DAMAGE, PERSONAL INJURY, AND/OR DEATH.
WARNING!
REMOVE THE GROUND CABLE FROM THE NEGATIVE
TERMINAL OF THE BATTERY BOX BEFORE DISCONNECTING ANY
ELECTRICAL COMPONENTS. ALWAYS CONNECT THE GROUND CABLE
LAST. FAILURE TO DO SO MAY RESULT IN PROPERTY DAMAGE,
PERSONAL INJURY, AND/OR DEATH.
1. Park vehicle on a flat surface.
2. Shift transmission to park or neutral and set spring brakes.
3. Install wheel chocks.
4. Release spring brakes using dash mounted air control valve.

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Figure 1. Spring Brake Label
1. Spring brake build date code

5. Inspect the build date code on both spring brake chambers (Figure 1). If the
date codes on the spring brake chambers are 11/03/2010 through
04/01/2012, proceed with Step 6 for each chamber to be replaced. If the date
codes on the spring brake chambers fall outside these dates, no further
action is required. Proceed to Step 26.

Figure 2. Spring Brake Chamber
1. Integral release bolt

6. Locate integral release bolt on back of spring brake chamber (Figure 2).

VEHICLE RECALL G – 12524

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Figure 3. Caging Spring Brake Chamber
WARNING: Do not exceed fully caged length and do not exceed 74 lb-ft
(100 N.m) torque on the integral release bolt at any time or damage may
occur which could prevent any further correct manual release of the spring
brake.
7. Cage spring brake chamber by turning integral release bolt counter-clockwise
until the power spring is fully caged or compressed (Figure 3).

Figure 4. Integral Release Bolt
Measurement
8. Parking brake spring is fully caged when the release bolt is up approximately
1 11/16 in / 33 mm from the run position (Figure 4).
9. Set spring brakes and drain truck air tanks.

VEHICLE RECALL G – 12524

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Figure 5. Slack Adjuster
1. Slack adjuster clevis pins (2)

10. Remove cotter pins from clevis pins. Remove clevis pins from yoke. Discard
cotter pins and retain clevis pins for reuse.
11. Adjust slack adjuster nut until slack adjuster is free from spring brake
chamber welded yoke.

Figure 6. Brake System Valves
1.
2.
3.
4.

Quick release valve
Spring brake hose
Service brake hose
ABS modulator valve

WARNING: Verify that no air pressure remains in the service brake
chamber before you proceed. Sudden release of compressed air can
cause serious personal injury and damage to components.
IMPORTANT: Be sure to mark air line from air-inlet port marked “Spring”
for reinstallation reference.
VEHICLE RECALL G – 12524

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12. Disconnect spring brake chamber hose from quick release valve (Figure 6,
Items 1 and 2).
13. Disconnect spring brake chamber hose from ABS modulator valve (Figure 6,
Items 3 and 4).
14. Remove two spring brake chamber mounting hex nuts from spring brake
assembly and remove spring brake chamber assembly from chassis. Discard
hex nuts.

Figure 7. Spring Brake Chamber
1. Spring brake air inlet port
2. Service brake air inlet port

15. Remove spring brake chamber hose and service brake hose from spring
brake chamber (Figure 7).
16. Apply thread sealant to brake hose threads before installation.
install spring brake chamber hose and service brake hose onto new spring
brake chamber assembly.
NOTE: When installing any MGM Magnum Performance Plus model
chamber, it is mandatory to position chamber so the breather tube is away
from the road surface. Failure to comply will void the brake warranty on
these models.
NOTE: Do not use an impact wrench to tighten retaining nuts to MGM brake
chamber.
17. Install spring brake chamber assembly onto chassis while properly aligning
the position of chamber air-inlet ports for alignment with brake system air
valves. Install two washers and new hex nuts onto spring brake chamber
assembly. Torque nuts to 133-155 lb-ft (180-210 N.m).
18. Adjust slack adjuster until aligned with spring brake chamber welded yoke
holes.

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19. Install clevis pins from step 10 and new cotter pins onto spring brake
chamber yoke.
20. Adjust the brake shoe to drum clearance by referring to the slack adjuster
manufacturer’s procedures.
21. Install spring brake chamber hose onto quick release valve.
22. Install spring brake chamber hose onto ABS modulator valve.
23. Verify adequate vehicle air system pressure and release spring brake.
24. Un-cage spring brake chamber by turning integral release bolt clockwise until
release bolt is seated to chamber housing.
25. With the aid of an assistant, apply service brake and hold. Using soapy
water, spray service brake and spring brake chamber hose connections.
Inspect for air leaks at air line fittings. If bubbles appear, repair as needed.
26. Set spring brakes.
27. Uninstall wheel chocks.

END OF SERVICE PROCEDURE
LABOR INFORMATION
Operation Number

Description

Time

A40-12524-1

Inspection only

0.3

A40-12524-2

Inspect and replace one chamber

0.8

A40-12524-3

Inspect and replace two chambers

1.2

CAMPAIGN IDENTIFICATION LABEL
Each vehicle corrected in accordance with this
campaign must be marked with a CTS-1075
Campaign Identification Label.
Complete the label and attach on a clean surface
next to the vehicle identification number (VIN) plate.

VEHICLE RECALL G – 12524

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ADMINSTRATIVE/DEALER RESPONSIBILITIES
WARRANTY CLAIMS
Warranty claim expense is to be charged to Warranty. Claims are to be
submitted in the normal manner, making reference to Safety Recall 12524.
It is important that the coding be completed properly to assist in processing the
warranty claim. Complete instructions will be found in the Warranty Policy
Manual, Section 7.1.8.
As with all claim submission, items acquired locally must be submitted in the
“Other Charges” tab. The cost of any bulk items (bag of cable tie straps, roll of
wire, barrel of oil, tube of silicone, etc.) should be prorated for the cost of the
individual pieces/amount used during each repair.

UNITED STATES AND POSSESSIONS
The National Traffic and Motor Vehicle Safety Act, as amended, provides that
each vehicle that is subject to a vehicle recall campaign must be adequately
repaired within a reasonable time after the owner has tendered it for repair. A
failure to adequately repair within 60 days after a tender of a vehicle is prima
facie evidence of failure to repair within a reasonable time. If the condition is not
adequately repaired within 60 days, the owner may be entitled to replacement
with an identical or reasonable equivalent vehicle at no charge, or to a refund of
the purchase price less a reasonable allowance for depreciation.
Dealers must correct all vehicles subject to this campaign at no charge to the
owner, regardless of mileage, age of vehicle, or ownership, from this time
forward.
Dealers should proceed immediately to make necessary correction to units in
inventory. All inventory vehicles subject to this recall campaign must be
corrected prior to sale, transfer or delivery. If vehicles have been sold or
VEHICLE RECALL G – 12524

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transferred and you are in receipt of Customer Notification Letters and
Authorization for Recall Service cards for those vehicles, the transfer location or
customer must be notified immediately from your dealer location.
Dealers must make every effort to promptly schedule an appointment with each
owner to repair his or her vehicle as soon as possible. However, consistent with
the customer notification, dealers are expected to complete the repairs on the
mutually agreed upon service date.
Dealers involved in the recall process will be furnished a listing of owner names
and addresses to enable them to follow up with owners and have the vehicles
corrected. Use of this listing must be limited to this campaign because the list
may contain information obtained from state motor vehicle registration records
and the use of such motor vehicle registration data for purposes other than this
campaign is a violation of law in several states.
CANADA
Dealers must correct all vehicles subject to this campaign at no charge to the
owner, regardless of mileage, age of vehicle, or ownership, from this time
forward.
Dealers should proceed immediately to make necessary correction to units in
inventory. All inventory vehicles subject to this recall campaign must be
corrected prior to sale, transfer or delivery. If vehicles have been sold or
transferred and you are in receipt of Customer Notification Letters and
Authorization for Recall Service cards for those vehicles, the transfer location or
customer must be notified immediately from your dealer location.
Dealers must make every effort to promptly schedule an appointment with each
owner to repair his or her vehicle as soon as possible. However, consistent with
the customer notification, dealers are expected to complete the repairs on the
mutually agreed upon service date.
Dealers involved in the recall process will be furnished a listing of owner names
and addresses to enable them to follow up with owners and have the vehicles
corrected. Use of this listing must be limited to this campaign because the list
may contain information obtained from state motor vehicle registration records
and the use of such motor vehicle registration data for purposes other than this
campaign is a violation of law in several states.
EXPORT
Export Distributors should proceed immediately to make necessary correction to
units in inventory. All inventory vehicles subject to this recall campaign must be
corrected prior to sale, transfer or delivery. If vehicles have been sold or
transferred and you are in receipt of Customer Notification Letters and
Authorization for Recall Service cards for those vehicles, the transfer location or
customer must be notified immediately from your distributor location.
VEHICLE RECALL G – 12524

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Export Distributors are to submit warranty claims in the usual manner making
reference to this recall number.
Export Distributors are expected to provide full cooperation and follow-up with
respect to this important subject matter. If you have any questions or need
further assistance, please contact the Regional Service Manager at your regional
office.

NAVISTAR, INC

VEHICLE RECALL G – 12524

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