CAMPAIGN: REAR BRAKE WHEEL CYLINDER ROTATION
MODELS: 1976-1979 CABALLERO LIGHT DUTY MODEL TRUCK 1982 S15 LIGHT DUTY MODEL TRUCK
The National Traffic and Motor Vehicle Safety Act, as amended, provides that each vehicle which is subject to a recall campaign of this type 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 tender of a vehicle is prima facie evidence of failure to repair within a reasonable time.
If the condition is not adequately repaired within a reasonable time, the owner may be entitled to an identical or reasonably equivalent vehicle at no charge, or to a refund of the purchase price less a reasonable allowance for depreciation.
To avoid having to provide these burdensome solutions, every effort must be made to promptly schedule appointments with owners and to repair their vehicles as soon as possible. As you will see in reading the attached copy of the letter which is being sent to owners, the owner is being instructed to contact the nearest GMC Zone Office if the dealer does not remedy the condition within five days of the mutually agreed upon service date. If the condition is not remedied within a reasonable time, they are instructed how to contact the National Highway Traffic Safety Administration.
DEFECT INVOLVED
General Motors has determined that a defect which relates to Motor Vehicle Safety exists in some 1978-1979 Caballero Model Trucks and 1982 S15 Model Trucks. It is possible that a rear brake wheel cylinder could rotate due to enlargement of the wheel cylinder pilot hole in the backing plate. If such rotation becomes excessive, contact could be lost between the wheel cylinder piston and the brake shoe and could result in the loss of rear brake fluid and consequently the loss of rear braking action.
These vehicles are equipped with a dual braking system. In the event of a rear system loss, the front brake system would remain functional and the brake warning light on the instrument panel would be lit. Absence of rear braking at a time when minimum stopping distance is required could result in a vehicle crash without prior warning.
To prevent the possibility of this condition occurring on vehicles involved, dealers are to install a retaining bracket on both rear wheel cylinders to prevent them from rotating. These parts are available in a parts kit from WDDGM.
Normal maintenance items such as worn brake linings, leaking wheel cylinder, and parking brake cables found during the campaign that require replacement will be at the customer's expense. Customer must be contacted and their consent obtained prior to replacement of any maintenance parts.
VEHICLES INVOLVED
Involved are certain 1978-1979 Caballero Model Trucks and certain 1982 S15 Model Trucks built within the following VIN breakpoints.
Year Model Plant From Through
1978 Caballero Doraville SOP EOP 1979 Caballero Doraville SOP EOP 1982 S15 Pontiac SOP EOP 1982 S15 Moraine SOP C2502789
The specific vehicles involved in this campaign have been identified by Vehicle Identification Number Computer Listings. These listings are furnished to all involved dealers with the campaign bulletin.
DEALER CAMPAIGN RESPONSIBILITY
Dealers are to service all vehicles subject to this campaign at no charge to owners, regardless of mileage, age of vehicle, or ownership, from this time forward.
Whenever a vehicle subject to this campaign is taken into your new or used vehicle inventory, or it is in your dealership for service in the future, you should take the steps necessary to be sure the campaign correction has been amde before reselling or releasing the vehicle.
Owners of vehicles recently sold from your new vehicle inventory are to be contacted by the dealer, and arrangements made to make the required modification according to instructions contained in this bulletin.
If no owner's name and address were available to GMC Truck at the time of campaign initiation, the dealer will determine the owner's name and address from the dealership sales records. Please provide this information directly on the second copy of the listing next to the applicable VIN, so that our records may be updated and the appropriate notification mailed to the owner. This second copy should then be submitted to the address listed below in the previously supplied yellow campaign envelopes.
GMC Truck General Motors Corporation 101 Union Street Plymouth, Michigan 48170
OWNER NOTIFICATION
Owners will be notified of this campaign on their vehicles by GMC Truck (see copy of Owner Letter included with this bulletin). A listing of owner names and addresses has been furnished to the involved dealers to enable dealers to follow up with owners involved in this campaign. This listing may contain owner names and addresses obtained from state motor vehicle registration records. The use of such motor vehicle registration data for any other purpose is a violation of law in several states. Accordingly, you are urged to limit the use of this listing to this campaign.
PARTS INFORMATION
Parts are to be obtained from the Warehousing and Distribution Division of General Motors (WDDGM). Tu ensure that these parts will be obtained as soon as possible, they should be ordered from WDDGM on a C.I.O. order with no special instruction code, but order on an advise code (2).
Parts Number Description Quantity per Vehicle
18013604 Wheel Cylinder Retainer Bracket Kit 1
Because of the limited number of parts available at the time of Campaign initiation, owner notification and parts distribution will take place on a regional basis until such time as an adequate supply is available.
SERVICE PROCEDURE
Using parts from kit part number 18013604, install a wheel cylinder retaining bracket on both rear wheel cylinders using the following procedure:
1. Hoist and support vehicle.
2. Use a brush or scraper to remove rust and dirt build-up from areas 1, 2, and 3 shown on Figure No. 1.
3. Place a wheel cylinder bracket over brake pipe with bracket fingers toward the wheel cylinder. Refer to Figure No. 2
THE RETAINER BRACKET MUST FIT FLUSH AGAINST THE BACKING PLATE MOUNTING FLANGE WITH ALL FOUR (4) BRACKET FINGERS EXTENDING INTO THE HOLE TO GRASP THE WHEEL CYLINDER.
In some cases, it may be necessary to reposition the wheel cylinder to properly install the bracket. If you cannot properly reposition the wheel cylinder, brake drum removal may be necessary. Contact your Zone Office Service Department for instructions regarding these additional procedures.
NOTE: Zone approval is required for this additional labor.
4. Insert the bolt from kit through the hole in the bracket and start into the clipped on nut. Using a #8 external Torx head socket, tighten bolt to 6.72 N.m (60 in. lbs.).
The bracket may tend to walk inward down the axle tube as the bilt is tightened.
WHEN THE BRACKET IS PROPERLY INSTALLED, THE GAP BETWEEN THE BRACKET AND MOUNTING FLANGE MUST NOT EXCEED 3MM (7/64"). REFER TO FIGURE NO. 3. IF GAP EXCEEDS 3MM, REMOVE BRACKET AND REPEAT STEPS 2, 3, AND 4.
5. Grasp the retaining bracket by hand and twist. Bracket should not move. If the bracket can be moved, it should be reinstalled, repeating steps 2,3, and 4.
6. Repeat steps 2, 3, 4, snd 5 to install a bracket on opposite side of vehicle.
WARRANTY INFORMATION
Dealer should submit an accurately filled out Warranty Repair Order on each vehicle completed under this campaign.
Labor Operation Number Description *Time Allowance Trouble Code
Install Bracket 0.4 Hrs. 96 Retainer Kit
V2860 1982 S15
V2860 00 1978-1979 Caballero
For dealer to receive Administrative Time Allowance associated with this campaign, add 0.1 hours to the labor Operation Time Allowance.
CAMPAIGN IDENTIFICATION LABEL
Each vehicle modified in accordance with the instructions outlined in this product campaign bulletin will require a "Campaign Identification Label". Each label provides a space to include the five (5) digit Dealer Code of the dealer performing the campaign service. This information may be inserted with a typewriter or ballpoint pen.
Each "Campaign Identification Label" is to be located on the radiator core support in an area which will be visible when the vehicle is brought in fur periodicc servicing by the owner.
Apply "Campaign Identification Label" only on a clean dry surface.
ADMINISTRATIVE PROCEDURE
Procedures covering this campaign are outlined in Section V of your dealership's "GMC Truck Claims Processing Manual" #SD8519.
Dear GMC Truck Owner
This notice is sent to you in accordance with the requirements of the National Tidilic and Motor Vehicle Safety Act.
General Motors has determined that a defect which relates to Motor Vehicle Safety exists in some 1978 and 1979 Caballero Model Trucks and 1982 S15 Model Trucks. It is possible that a rear brake wheel cylinder could rotate due to enlargement of the wheel cylinder pilot hole in the backing plate. If such rotation becomes excessive, contact could be lost between the wheel cylinder piston and the brake shoe and could result in the loss of rear brake fluid and consequently the loss of rear braking action.
These vehicles are equipped with a dual braking system. In the event of a rear system loss, the front brake system would remain functional, and the brake warning light on the instrument panel would be lit. Absence of rear braking at a time when minimum stopping distance is required could result in a vehicle crash without prior warning.
To prevent this from occurring on your vehicle, please contact your GMC Truck Dealer to arrange a service date. The dealer will install a wheel cylinder retaining bracket kit which will prevent the wheel cylinders from rotating,
Instructions have been sent to your GMC Truck Dealer. Parts are currently available in your area. The labor time necessary to do this work will be about twenty five (25) minutes. Please ask your dealer if you wish to know how much additional time will be necessary to process your vehicle.
Until you have had an opportunity to have this service completed, you should be alert for an increase in brake pedal travel during brake application and illumination of the brake warning light on the instrument panel. If either of these conditions occurs, you should contact your dealer immediately for service.
Your GMC Truck Dealer is best equipped to obtain parts and provide service to ensure your vehicle is corrected as promptly as possible. However, if you take your vehicle to your dealer on the agreed service date, and they do not remedy this condition on that date or within five days, we recommend you contact the nearest GMC Truck Zone Office, either in person or by telephone. The Zone Office will assist you and the dealer in getting your vehicle corrected. The locations and telephone numbers of the Zone Offices are listed in your Owner's Manual.
After contacting your dealer and the Zone Office, if you are still not satisfied that we have done our best to remedy this condition without charge and within a reasonable time, you may wish to write the Administrator, National Highway Traffic Safety Administration, 400 Seventh Street, S.W, Washington, D.C. 20590 or call 800-424-9393 (Washington, D C residents use 426-0123).
The enclosed owner reply card identifies your vehicle. Presentation of this card to your dealer will assist in making the necessary correction in the shortest possible time. If you have sold or traded your vehicle, please let us know by completing the postage paid owner reply card and returning it to us.
We are sorry to cause you this inconvenience, however, we have taken this action in the interest of your safety and continued satisfaction with our products.
General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.
