CAMPAIGN : INCORRECT REAR BRAKE SYSTEM (JA2)

Models: 1984 Century Wagons

DEFECT INVOLVED:

General Motors of Canada has determined that some 1984 Century Wagons were assembled with a JA2 rear brake system instead ot the correct JA3 brake system. These vehicles fail to conform to the requirements of Canadian Motor Vehicle Safety Standard 105 "Hydraulic Brake Systems". Under certain conditions, these vehicles may exceed the required maximum stopping distance permitted by CWSS 105. Should a stopping distance conforming with CWSS 105 be required while the vehicle is being driven, a vehicle crash could occur without prior warning.

DEALER ACTION

Dealers are to install the correct JA3 brake system parts on vehicles involved as instructed in the "Technical Procedure" of this bulletin. Parts to be replaced are rear brake assemblies, rear brake drums, and master cylinder proportioner valves.

VEHICLES INVOLVED:

Certain 1984 Century Wagons which were assembled with JA2 brake systems with the following Vehicle Identification Numbers:

UP TO ASSEMBLY PLANT BEGINNING VIN AND INCLUDING -------------- ------------- ------------- Doraville ED451639 ED464800 Oklahoma City E6510488 E6545193

If your Dealership has vehicles involved in this campaign, you will receive the following items:

List of all vehicles involved in their campaign shipped to your Dealership.

One (1) JA3 brake systen identification label.

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 now 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:

Parts required for this campaign should be ordered through regular channels as follows:

DESCRIPTION USAGE PART NUMBER QUANTITY ------------ ----- ----------- -------- * Package, Rear Brake 1984 Century Wagons 18012746 1 Per Assembly & Proportioner with Gas Engines Vehicle valve

* Package, Rear Brake 1984 Century Wagons 18012747 1 Per Assembly & Proportioner with Diesel Engines Vehicle valve

Rear Brake Drum 1984 Century Wagons 25518892 2 Per Vehicle

* These packages included a right and a left rear brake assembly (backing plate with wheel cylinder, brake shoes installed), and two (2) brake proportioner valves.

DO NOT ORDER A BRAKE PACKAGE UNLESS YOU HAVE A VEHICLE INVOLVED IN THIS CAMPAIGN. THESE PACKAGES ARE AVAILABLE IN LIMITED QUANTITIES.

DISPOSITION OF PARTS

Replaced parts must be held for disposition by Zone Personnel. Parts must have a claim tag attached showing the repair order and the VIN of the vehicle from which they were removed.

PARTS AND LABOUR CLAIN 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 JA3 1.9 Brake System Parts

Time allowance includes 0.1 hour for Dealer administrative detail associated with this campaign. Parts credit will be based on Dealor net plus 30% to cover parts handling, plus an allowance of $6.00 for brake fluid.

SERVICE PROCEDURE

1. Open vehicle hood and cover fenders.

2. Place material under proportioner valve connections to protect under hood parts from brake fluid.

3. Refer to Figure #1 and replace front and rear brake proportioner valves.

4. Replace right and left rear brake assemblies using the following procedure on each side.

(a) Hoist vehicle.

(b) Remove rear wheal and tire assembly.

(c) Remove rear brake drum.

Do not hammer on brake drum, as damage to bearings could result.

(d) Disconnect brake pipe from wheel cylinder.

(e) Remove the hub and bearing assembly using a #50 torx driver tool (Special Tool #J-23457).

(f) Reinstall one sounting bolt to hold the backing plate to the axle.

(g) Disconnect the parking brake cable from the backing plate by depressing three pronge with 3 screwdriver while pulling the cable out.

(h) Loosen the parking brake adjuster until all the tension is removed from the parking brake cable return spring.

(i) Remove the parking brake strut and spring.

(j) Disconnect the parking brake cable end from the parking brake lever.

(k) Remove the backing plate assembly.

(l) Renove the parking brake strut and spring from the new backing plate assembly and set them aside.

(m) Insert the parking brake cable part way into the new backing plate. Connect the parking brake cable end to the parking brake lever. Then push the cable all the way into the new backing plate until it locks.

(n) Reinstall the parking brake strut and spring.

(o) Install the new backing plate assembly and the hub and bearing assembly on the axle and torque the mounting bolts to 60 N.n (45 ft. lbs.).

(p) Reconnect the brake pipe and torque to 20 N.ft (15 ft. lbs.).

5. Inspect both backing plate assemblies to insure all parts are present and properly installed.

6. Install the new brake drums and adjust the brake shoes per 1984 Chassis Service Manual reference page 5-36.

7. Reinstall the rear wheel and tire assemblies and torque lug nuts to 140 N.m (100 ft. lbs.).

8. Adjust the parking brake cable so that, with the parking brake pedal depressed three (3) clicks, the right-rear wheel can just be turned rearward using two hands, but is locked when forward rotation is attempted. Refer to page 5-34 in the 1984 Chassis Service Manual. It is important that the parking brake is not adjusted too tightly as this would cause brake drag.

9. Remove and discard the rear axle bar code label located on trailing axle assembly.

10. Lower vehicle and bleed the brake system at rear wheel cylinders until all air is removed. Refer to page 5-12, 5-13, and 5-14 in the 1984 Chassis Service Manual.

11. Fill master cylinder to proper level and check brake system for any leaks. Correct leaks as required.

12. Affix furnished JA3 identification label next to the Service Parts Identification Label. This label is located near the right rear wheel well under spare tire cover.

13. Remove and discard the master cylinder bar code label.

14. 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 requirements of the Canada Motor Vehicle Safety Act.

General Motors of Canada has determined that some 1984 Century Wagons were assembled with a JA2 rear brake system instead of the correct JA3 brake system. These vehicles fail to conform to the requirements of Canadian Motor Vehicle Safety Standard 105 "Hydraulic Brake Systems". Under certain conditions, these vehicles may exceed the required maximum stopping distance permitted by CNVSS 105. Should a stopping distance conforming with CNVSS 105 be required while the vehicle is being driven, a vehicle crash could occur without prior warning.

To remedy this nonconformance with CMVSS 105, your GM dealer will install the correct rear brake system parts on your vehicle. This service will be performed at no charge to you.

Please contact your Dealer to arrange a service date. The labour time to complete this service is about two (2) hours. Please ask your Dealer how much additional time will be needed to process your vehicle. 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. Your prompt cooperation would be appreciated.

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.