FMVSS Non-Compliance - Front Brake Pipe Union Leak

ON AUGUST 3, 1999, ALL MODEL YEAR 2000 CHEVROLET AND GMC 2WD S-TRUCKS BUILT AT LINDEN AND SHREVEPORT WERE PLACED ON STOP DELIVERY. THIS CAMPAIGN BULLETIN WILL RELEASE VEHICLES FROM STOP DELIVERY ONCE THE SERVICE PROCEDURE HAS BEEN COMPLETED.

General Motors has decided that certain 2000 model year Chevrolet and GMC 2WD S-Trucks built at Linden and Shreveport Assembly Plants may fail to conform to Federal Motor Vehicle Safety Standard (FMVSS) 105, "Hydraulic Service Brake-Normal, Emergency, and Park Braking Performance." These vehicles may have had the right-hand ABS (Antilock Brake System) module feed pipe and/or brake crossover pipe tube nuts tightened without seating the pipe-flared-ends enough to withstand normal assembly and vehicle inputs without partially unseating. If this occurred, the seating seal could be broken during vehicle assembly, or from early road inputs or brake fluid cycling, and a leak could occur. If this occurred when minimum stopping distance was required, it could result in a vehicle crash.

To correct this condition, dealers are to inspect the union for signs of brake fluid, and if necessary, install a new union.

Involved are the following six (6) GMODC model year 2000 Chevrolet 2WD S-truck model vehicles built at Shreveport Assembly Plants:

Involved vehicles have been identified by Vehicle Identification Number. Computer listings containing the complete Vehicle Identification Number, customer name and address data have been prepared, and are being furnished to involved dealers with the campaign bulletin. The customer name and address data furnished will enable dealers to follow-up with customers involved in this campaign. Any dealer not receiving a computer listing with the campaign bulletin has no involved vehicles currently assigned.

Parts required to complete this campaign are to be obtained from General Motors Service Parts Operations (GMSPO). Please refer to your "involved vehicles listing" prior to ordering requirements.

Registered letters will be sent to known owners of record located within areas covered by the U.S. National Traffic and Motor Vehicle Safety Act, as amended. For owners outside these areas, the attached suggested dealer letter is recommended and should be sent by dealers.

All unsold new vehicles in dealers' possession and subject to this campaign MUST be held and inspected/repaired per the service procedure of this campaign bulletin BEFORE customers take possession of these vehicles.

Dealers are to service all vehicles subject to this campaign at no charge to customers, regardless of mileage, age of vehicle, or ownership, from this time forward.

Customers who have recently purchased vehicles sold from your vehicle inventory, and for which there is no customer information indicated on the dealer listing, are to be contacted by the dealer. Arrangements are to be made to make the required correction according to the instructions contained in this bulletin. This could be done by mailing to such customers a copy of the customer letter accompanying this bulletin. Campaign follow-up cards should not be used for this purpose, since the customer may not as yet have received the notification letter.

In summary, whenever a vehicle subject to this campaign enters your vehicle inventory, or is in your dealership for service in the future, please take the steps necessary to be sure the campaign correction has been made before selling or releasing the vehicle.

Inspection Procedure

1. With the engine running and the automatic transmission in PARK or manual transmission in neutral with the parking brake set, pump the brake pedal 5 times and hold the pedal fully depressed.
2. Continue to hold the brake pedal down. Turn the wheels to the right and turn the ignition to OFF.

Important: A second technician is required for visual inspection

3. With the brake pedal still applied, wait 30 seconds and have the second technician lift the left rubber inner fender well flap and inspect for brake fluid leakage at the right-hand ABS feed pipe and brake crossover pipe union.

-	If no leakage is present, no further action is required. Install the GM Campaign Identification Label.

-	If a leak is present, proceed to the Repair Procedure below.

Important: If a leak if found, DO NOT attempt to re-torque the tube nuts. The union must be replaced.

Repair Procedure

1. Raise the vehicle.
2. Remove the left-hand tire and wheel assembly.
3. Tape the rubber inner fender well flap to the inner fender well for access to the union.
4. Place shop rags under the union and pipe to prevent contact of brake fluid on the frame and other components.
5. Remove the union.
6. Install the new union by finger starting the tube nuts to the union.

Tighten

•	Tighten the upper tube nut to 24 N·m (18 lb ft) while holding the position of the union.

•	Tighten the lower tube nut to 24 N·m (18 lb ft) while holding the position of the union.

7. Clean the union and the affected area.
8. Verify that the brake lines are securely engaged in the clip located above the union.
9. Bleed the right front brake circuit.

-	Fill the master cylinder reservoir with DOT 3 motor vehicle brake fluid.

-	Place a clear tube over the caliper bleeder valve.

-	Immerse the opposite end of the hose into a clear container partially filled with clean brake fluid.

-	Slowly apply the brake pedal one time and hold.

-	Loosen the bleeder valve using J 21472 in order to purge the air from the brake line.

-	Tighten the bleeder valve and slowly release the brake pedal.

-	Wait 15 seconds.

-	Repeat the above sequence, including the 15 second wait, until all air is purged from the system.

Tighten
Tighten the bleeder valve to 7 N·m (62 lb in).

10. Clean any brake fluid off of the vehicle.
11. Fill the master cylinder reservoir to the proper level.
12. Remove the tape from the rubber inner fender well flap and return it back to the proper position to avoid contact with the brake pipes.
13. Install the left-hand tire and wheel assembly.

Tighten
Tighten the wheel nuts to 140 N·m (100 lb ft).

14. Lower the vehicle.
15. Perform the inspection procedure above.
16. Install the GM 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 the five (5) digit dealer code of the dealer performing the campaign service. This information may be inserted with a typewriter or a ball point 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 by the customer for periodic servicing. Additional Campaign Identification Labels can be obtained from your Regional Marketing Office.

Apply the "Campaign Identification Label" only on a clean, dry surface.

Submit a Product Campaign Claim with the information indicated below.

Refer to the General Motors Corporation Claims Processing Manual for details on Product Campaign Claim Submission.