CAMPAIGN: WHEEL CYLINDER ROTATION-DUAL BRAKE SYSTEM

Models: 1978-81 A, A spl. G; 1982-84 G; 82 S Truck; 83 S/T Trucks

DEFECT INVOLVED:

Transport Canada has advised General Motors of Canada that they believe a safety related defect may exist on certain 1978 to 1984 Malibu, Monte Carlo, El Camino, LeMans, Grand LeMans, Grand Prix, Cutlass, Cutlass Supreme, Century, Regal, Caballero models, 1982 'S' Trucks and some 1983 S/T Trucks. Specifically, Transport Canada is concerned that these vehicles may develop a rear wheel brake cylinder rotation condition which, if excessive, may result in the loss of brake fluid in the rear brakes and the loss of rear braking capability.

These vehicles 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 and there would be an increase in brake pedal travel. The front brake system would remain fully functional allowing the vehicle to be stopped, but over a greater distance.

VEHICLES AFFECTED ----------------- CHEVROLET --------- Malibu, Monte Carlo, El Camino Lansing 78-79-80 Plt M Leeds 80 Plt K Freemont 78-79-80 Plt Z Doraville 80 Plt D

S-TRUCK

Moraine 82 C2111110 to EOP

PONTIAC

LeMans, Grand LeMans, Grand Prix Pontiac 79-80 Plt P

OLDSMOBILE

Cutlass, Cutlass Supreme Doraville 80 Plt D Framingham 79-80 Plt G

BUICK

Century, Regal Flint 78-79 Plt H Framingham 79-80 Plt G

GMC

Caballero Doraville 80 Plt D

S-TRUCK

Moraine 82 C2502790 to EOP

All 83 S/T Trucks. All 1981 A, A Spl, Pontiac G. All 1982-83 G Models

1984 G models as follows:

Oldsmobile Ste Therese SOP to E2347201 * Pontiac Ste Therese SOP to E2268857 Buick Flint SOP to EH551035 Chevrolet Baltimore SOP to EB124514

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:

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

In the event that a backing plate and wheel cylinder is required for vehicles involved in this recall, the following part nos. should be used:

Monte Carlo, Malibu, El Camino Assembly LH 18013045 LeMans, Grand Prix Cutlass, Backing Plate RH 18013046 Century, Regal, GMC Caballero & Wheel Cyl.

S/T Truck Assembly LH 18013047 Backing Plate RH 18013048 & Wheel Cyl

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

3A Install Bracket Retainer Kit 1.2* Replace one backing plate and wheel cylinder assembly 4A Install Bracket Retainer Kit 1.6* Replace two backing plate and wheel cylinder assemblies

An allowance of $14.00 will be included in 3A and $15.50 in 4A to allow for differential oil, gasket, axle seals and brake fluid. The usual .1 for administration is also included. Parts credit will be dealer net plus 30%.

Normal maintenance items such as worn brake linings 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 parts not covered by the campaign.

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 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.

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.

5. After the bracket has been installed please proceed as follows:

Inspect to make sure that the bracket fingers grasp the wheel cylinder.

Check gap between the bracket and mounting flange (must not exceed 3mm (7/64").

Grasp retaining bracket by hand and twist to see if it moves.

If gap exceeds 3mm (7/64") or can be moved by twisting, it should be reinstalled (repeat steps 2, 3, 4, 5).

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.

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.