CAMPAIGN: ENGINE FUEL LINE AND ACCEL CABLE BRKT. INTERFERENCE

SUBJECT: ENGINE FUEL LINE/ACCELERATOR CABLE BRACKET INTERFERENCE

MODELS: 1992 W6/W7 GMC FORWARD - CHEVROLET TILTMASTER

General Motors has learned that certain 1992 W6/W7 GMC Forward - Chevrolet Tiltmaster vehicles have the potential for an interference condition between an engine diesel fuel line and a mounting bolt for the accelerator cable bracket. If an interference condition were to occur, after some period of time, engine vibration/resonance could produce a fuel line leak.

To prevent this condition from occurring, it will be necessary to inspect for the desired clearance and replace the accelerator bracket mounting bolt or adjusting the accelerator bracket as required.

VEHICLES INVOLVED

Involved are certain 1992 W6/W7 GMC Forward - Chevrolet Tiltmaster vehicles. Involved VIN's are listed below in dealer code order.

DEALER CODE VIN ----------- ----------------- 13-13038 J8BH6A1U8N3100207 13-30360 J8BK7A1U0N3200451 13-26358 J8BM7A1U7N3300068 48-06280 J8DK7A1U8N3200415 48-06280 J8DM7A1U9N3200447 48-06295 J8DH6A1U2N3100209 48-06295 J8DM7A1U6N3200521 48-06306 J8DK7A1U3N3200435 48-10075 J8DM7A1U0N3200580 48-10356 J8DM7A1U4N3200470 48-10684 J8DK7A1U3N3200483 48-21172 J8DK7A1U6N3200459 48-21212 J8DM7A1U6N3300067 48-21676 J8DK7A1U5N3200422 48-21676 J8DK7A1U4N3200430 48-21676 J8DK7A1U1N3200434 48-21676 J8DK7A1U1N3200479 48-21676 J8DM7A1U3N3300060

48-21676 J8DM7A1U2N3300065 48-21676 J8DM7A1U4N3300066 48-26061 J8DK7A1U2N3200488 48-26170 J8DM7A1U0N3200417 48-26170 J8DM7A1U6N3200423 48-26170 J8DM7A1U5N3200431 48-26170 J8DM7A1U4N3200436 48-26170 J8DM7A1U1N3200443 48-26170 J8DM7A1U2N3200452 48-26170 J8DM7A1U3N3200458 48-26170 J8DM7A1U0N3200465 48-26170 J8DM7A1U7N3300076 48-30573 J8DH6A1U9N3100241 48-40146 J8DH6A1U6N3100200 48-42046 J8DK7A1U9N3200519 48-42240 J8DK7A1U4N3200444 48-47288 J8DK7A1U3N3200497 48-53013 J8DH6A1UXN3100202 48-53013 J8DH6A1U5N3100205 48-53013 J8DH6A1U0N3100211 48-53013 J8DH6A1U4N3100213 48-53013 J8DH6A1U1N3100220 48-53013 J8DH6A1U2N3100226 48-53013 J8DH6A1U4N3100230 48-53013 J8DH6A1U3N3100235 48-53013 J8DH6A1U8N3100246 48-53013 J8DH6A1U1N3100279 48-53013 J8DH6A1U1N3100296 48-53013 J8DK7A1U5N3200484 48-53077 J8DK7A1U8N3200463

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. Dealers are to correct all affected vehicles in new and used vehicle stock prior to their sale.

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 ensure 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 cor- rection according to instructions contained in this builetin.

If the name and address of the owner of an involved vehicle was unavailable to GMC Truck Division at the time of campaign initiation, the dealer must 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 Division General Motors Corporation 101 Union Street Plymouth, Michigan 48170

OWNER NOTIFICATION

Owners will be notified of this campaign on their vehicles by GMC Truck Division (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.

SERVICE PROCEDURE INSPECTION AND BOLT REPLACEMENT

1. Block wheels and tilt cab

2. Measure gap between fuel return pipe and stop cable bracket bolts (Figure 2). If gap is larger than 3 mm (0.11 in.) no modification is necessary. If the gap is smaller than 3 mm (0.11 in.) modification is necessary.

3. Remove the stop cable bracket bolts (Figure 1 "D") and reassemble with replacement bolts.

4. Measure gap between the fuel pipe and bolts (Figure 2). If gap is larger than 3 mm (0.11 in.) no further modification is needed. If gap is smaller than 3 mm (0.11 in.) perform the adjustment procedure below.

ADJUSTMENT PROCEDURE

1. Set throttle adjust knob (inside cab) to minimum position (fully counter clockwise). 2. Turn ignition key to "ON" position (engine off). 3. Loosen transmission cable clip (Figure 1 "A"). 4. Loosen engine control (accelerator) cable clip bolts (Figure 1 "B"). 5, Remove engine cable stop cotter pin and disconnect cable from link pin (Figure 1 "C"). 6. Loosen the two bolts securing the stop cable bracket (Figure 1 "D"). 7. Loosen the two 12 mm bolts (Figure 1 "E") securing the stop cable bracket to the manifold (Figure 1). 8. Adjust the stop cable bracket forward and/or aft to obtain 3 mm (0.11 in.) or greater clearance from bolt to fuel pipe. 9. Retighten the two 12 mm bolts (Figure 1 "E") securing stop cable bracket to manifold. 10. Verify clearance from bolt to fuel pipe (Figure 2). 11. Retighten cable control clip to engine stop bracket (Figure 1 "B"). 12. Adjust engine control cable (Figure 1 "F") to insure no slack is in the engine control cable. 13. Reattach the engine stop cable and reinstall the washer and cotter pin (Figure 1 "C"). 14. Retighten the two bolts securing the engine stop cable stop bracket (Figure 1 "D"). 15. Tighten transmission cable clip (Figure 1 "A"). 16. Verify the throttle opens completely when the accelerator is depressed (engine not running). 17. Start engine and verify throttle operation. 18. Turn ignition off and verify the engine stops and the engine stop cable functions correctly. 19. Install "Campaign Identification Label".

PARTS INFORMATION

Parts should be ordered directly from American Isuzu Parts Distribution Network (AIPDN). Parts may also be obtained from General Motors Service Parts Operation (GMSPO) on an order type ISC.

Part Number Description Quantity -------- ------------------------ -------- 94005022 Bolt, M8 x 1.26 16mm long 2

WARRANTY INFORMATION

Dealers should submit a warranty claim on each vehicle completed under this campaign.

Labor Operation 'Time Trouble Number Description Allowance Code

V7150 Inspect and Adjust 0. 6 H rs. 96 Accelerator Bracket

For dealer to receive Administrative Time Allowance associated with this campaign, add 0.1 hour to the Labor Operation Time Allowance.

CAMPAIGN IDENTIFICATION LABEL

Each vehicle corrected 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 campaign number and five (5) digit dealer code of the dealer performing the campaign service. This infor- mation may be inserted with a typewriter or ball point pen. Each "Campaign identification Label" is to be located on the cab inner panel 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"GM Truck Claims Processing Manual" #P9119.

Dear General Motors Truck Owner:

General Motors has learned that certain 1992 W6/W7 GMC Forward - Chevrolet Tiltmaster vehicles have the potential for an interference condition between an engine diesel fuel line and a mounting bolt for the accelerator cable bracket. If an interference condition were to occur, after some period of time, engine vibration/resonance could pro- duce a fuel line leak.

To prevent this condition from occurring, it will be necessary to inspect for the desired clearance and replace the accelerator bracket mounting bolt or adjusting the accelerator bracket as required. This service will be completed for you at no charge.

Instructions for making this correction have been sent to your GM dealer. Please contact your dealer as soon as possible to arrange a service date. Ask your dealer if you wish to know how much time will be needed to schedule, process and repair your vehicle.

The enclosed postage paid owner reply card identifies your vehicle. Presentation of this card to your dealer will assist in making the necessary correction to your vehicle in the shortest possible time. If you have sold or traded your vehicle, please furnish us the complete name and address of the person to whom you sold or traded your vehicle and return the card to us.

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