CAMPAIGN: BRACKET INTERFERENCE RUBBING THROUGH BRAKE LINE

MODELS: 1983 CABALLEROS EQUIPPED WITH 5.7L V-8 DIESELS RPO LF9

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 a service date with each owner and to repair their vehicle 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 their 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 1983 Caballeros equipped with 5.7 liter V-8 diesel engines. The rear brake master cylinder brake pipe may rub on the air cleaner resonator bracket. Over an extended period of operation, the brake pipe, could wear through, resulting in a brake fluid leak and loss of the rear brakes. These vehicles are equipped with dual braking systems; part of the system will still work and allow the vehicle to be stopped, but over a greater distance. Loss 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 determine if there is a minimum of 19mm (3/4 inch) clearance between the brake pipe and resonator bracket, and if required reposition pipe to provide this clearance. Also if this pipe is worn due to contacting the bracket, the pipe is to be replaced.

VEHICLES INVOLVED

Involved are certain 1983 Caballeros equipped with RPO LF9, 5.7L diesel engine and identified within the following vehicle breakpoints:

Plant From Through ----- ---- ------- Arlington SOP DR401437

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 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.

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

Brake Pipe, Part Number 25513371, if required for this campaign is to be obtained from WDDGM. Very few pipes will require replacement on vehicles inspected.

To ensure this part will be obtained as soon as possible, it should be ordered from GM Parts (WDDGM) on a C.I.O. order with no special instruction code, but order on an advise code (2). Parts will be available 10-31-83.

SERVICE PROCEDURE

1. Open vehicle hood and check to determine if the rear brake system pipe from master cylinder to proportioner valve has a minimum clearance of 3/4 inch to the air cleaner resonator bracket. Refer to Figure No. 1 and Figure No. 2 - View A.

2. If the brake pipe has been contacting the bracket and has a shiny or wom spot due to this contact, replace pipe with part number 25513371. Refer to Section 5 of the 1983 Caballero Service Manual for brake bleeding information and Figure No. 2 - for required pipe clearances.

3. If clearance is less than specified, reform the pipe to provide 3/4 inch clearance. If the pipe is replaced due to wear, be sure to provide 3/4 inch clearance between it and the resonator bracket, and properly refill the system with brake fluid and bleed to ensure performance.

WARRANTY INFORMATION

Dealers should submit an accurately filled out Warranty Repair Order on each vehicle completed under this campaign.

Labor *Time Operation Allow- Trouble Number Description ance Code ------ ----------- ---- ---- V1830 Inspect vehicle .2 96 and reposition brake pipe

V1831 Inspect and replace .5 96 brake pipe

*For dealer to receive Administration Time Allowance associated with this campaign, add 0.1 hour 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 sevice. 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 for periodic 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" issued October, 1981.

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.