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CAMPAIGN: REAR BRAKE WHEEL CYLINDER ROTATION

Models: 1978-79-80 A, A spl, G, 1982 'S' Trucks

TO: ALL GENERAL MOTORS DEALERS

CONDITION

General Motors of Canada has determined that a defect which relates to motor vehicle safety may exist in some Malibu, Monte Carlo, El Camino, Lemans, Grand LeMans, Grand Prix, Cutlass, Cutlass Supreme, Century, Regal, Caballero and some 1982 S Trucks. It is possible that a rear brake wheel cylinder could rotate and lose piston contact with a brake shoe due to enlargement if the wheel cylinder pilot hole in the backing plate.

This condition would result in the loss of rear brake fluid and loss of the vehicle's rear brake system.

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.

VEHICLES INVOLVED:

Certain 1978-79-80, Chevrolet Malibu, Monte Carlo, El Camino; Pontiac LeMans, Crand Prix; Oldsmobile Cutlass, Cutlass Supreme; Buick Century, Regal, GMC Caballero, and some 1982 Chevrolet & GMC 'S' Trucks assembled at the following plants:

CHEVROLET

Malibu, Monte Carlo, El Camino

Oshawa 1978-79-80 Plant 1 Doraville 1978-79 Plant D Baltimore 1978-79-60 Plant B

S/Trucks 1982 Plant 2 to C2111109 Plant 0 All

PONTIAC

LeMans, Grand LeMans, Grand Prix

Oshawa 1978-79-80 Plant 1 Ste. Therese 1978-79-80 Plant 2 Baltimore 1978-79-80 Plant B Pontiac 1978 Plant P

OLDSMOBILE

Cutlass, Cutlass Supreme

Ste Therese 1978-79-60 Plant 2 Doraville 1978-79 Plant D Framingham 1978 Plant C

BUICK

Century, Regal

Framingham 1980 Plant G Flint 1978 Plant H

GMC

Caballero

Baltimore 1978-79-80 Plant B Doraville 1978-79 Plant D S/Truck 1982 Plant 2 to C2502789 1982 Plant 0 All

All affected vehicles have been identified by the VIN listing provided to involved dealers with this bulletin. Any dealer not receiving a listing was not shipped any of the affected vehicles.

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 made 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.

CAMPAIGN PROCEDURE:

Refer to Section 4 of the Service Policies and Procedures Manual for the detailed procedure on handling Product Campaigns. Dealers are requested to complete the campaign on all transfers as soon as possible.

OWNER NOTIFICATION:

All owners of record at the time of campaign release are shown on the attached computer listing and have been notified by first class mail from General Motors. The listings provided are for campaign activity only and should not be used for any other purpose.

PARTS INFORMATION:

It is expected parts will be in very short supply initially. Therefore, partial shipments will be generated by us automatically (10%) as parts become available. When 40% of requirements have been shipped we will open to dealer orders.

One Wheel Cylinder Retainer Bracket Kit, Part Number 18013604 is required for each vehicle involved in this campaign.

PARTS AND LABOUR CLAIM INFORMATION:

Credit for the campaign work performed will be paid upon receipt of a properly completed campaign claim card or RAPID terminal transmission in accordance with the following:

Repair Code Operation Time Allowance ----------- --------- -------------- 2A Install Bracket Retainer Kit .5

Time allowance includes 0.1 hour for Dealer administrative detail associated with this campaign. Parts credit will be based on dealer net plus 30% to cover parts handling.

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 1.

3. Place a wheel cylinder bracket over brake pipe with bracket fingers toward the wheel cylinder. Refer to Figure 2.

THE RETAINER BRACKET MUST FIT FLUSH AGAINST THE BACKING PLATE MOUNTING FLANGE WITH ALL FOUR (4) BRACKET FINEERS 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 neceseary. Contact your District Service Manager or the Technical Assistance Centre for instructions regarding these additional procedures.

NOTE: Zone approval is required for this additional labour.

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 bolt 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 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, and 5 to install a bracket on opposite side of vehicle.

7. Lower vehicle and install a campaign identification label.

INSTALLATION OF CAMPAIGN IDENTIFICATION LABEL

Clean surface of radiator upper mounting panel and apply a Campaign Identification Label. Make sure the correct campaign number is inserted on the label. This will indicate that the campaign has been completed.

Dear General Motors Customer:

This notice is sent to you in accordance with the Canada Motor Vehicle Safety Act.

General Motors of Canada has determined that a defect which relates to motor vehicle safety exists in some 1978, 1979, 1980 Malibu, Monte Carlo, El Camino, Lemans, Grand Lemans, Grand Prix, Cutlass, Cutlass Supreme, Century, Regal, Caballero, and some 1982 'S' Trucks produced in certain assembly plants. The condition relates to a possible enlargement of the wheel cylinder pilot hole in the rear brake backing plate which could contribute to wheel cylinder rotation. Such rotation, if excessive, may result in loss of brake fluid in the rear brakes.

These vehicle are equipped with a dual braking system. In the event of a loss of fluid in the rear system, the brake warning light on the instrument panel will illuminate. The front brake system would remain functional allowing the vehicle to be stopped, but over a greater distance. Should the rear brake fluid be lost at a time when minimum stopping distance is required, a vehicle crash could occur without prior warning.

To prevent this from occurring on your vehicle, please contact your GM Dealer to arrange a service date. The dealer will install a wheel cylinder retainer kit which will prevent the wheel cylinders from rotating.

Instructions have been sent to your GM Dealer. The labour time necessary to do this work will be about 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. In the event that either of these warnings is encountered, you should immediately contact your nearest GM Dealer.

This letter identifies your vehicle. Presentation of this letter to your Dealer will assist their Service personnel in completing the necessary correction to your vehicle in the shortest possible time.

Further assistance, if required, may be obtained from the General Motors Zone Office nearest you. Your vehicle Owner's Manual provides the location and phone number of each respective Zone Office.

We are sorry to cause you this inconvenience; however, we have taken the action in the interest of your continued satisfaction with our products.


Object Number: 75745  Size: FS


Object Number: 89164  Size: FS


Object Number: 81814  Size: FS

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.