Customer Satisfaction - 6-Speed Manual Transmission (RPO ML6) - Replace Reservoir Cap and Hydraulic Fluid

General Motors has decided that certain 2001 Chevrolet Silverado and GMC Sierra 2500HD and 3500 model vehicles equipped with an 8.1L gasoline (RPO L18 -- VIN Code G) or 6.6L Diesel (RPO LB7 -- VIN Code 1) engine, and a 6-speed manual transmission (ML6), may exhibit a condition in which the clutch fluid is contaminated by water that has been introduced through the reservoir cap. If the vehicle is operated at elevated transmission temperatures such as during heavy load hauling, this condition can cause loss of clutch pedal function until the clutch fluid cools below the fluid boiling point.

Dealers are to replace the clutch master cylinder fluid reservoir cap with a new part number cap, and drain and refill the reservoir with new hydraulic fluid.

Involved are certain 2001 Chevrolet Silverado and GMC Sierra 2500HD and 3500 model vehicles equipped with an 8.1L (RPO L18) or 6.6L (RPO LB7) engine and a 6-speed manual transmission (ML6) and built within these VIN breakpoints:

Important: Dealers should confirm vehicle eligibility through GMVIS (GM Vehicle Inquiry System) or GM Access Screen (Canada only) prior to beginning campaign repairs. [Not all vehicles within the above breakpoints may be involved.]

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.

These dealer listings may contain customer names and addresses obtained from Motor Vehicle Registration Records. The use of such motor vehicle registration data for any other purpose is a violation of law in several states/provinces/countries. Accordingly, you are urged to limit the use of this listing to the follow-up necessary to complete this campaign.

Parts required to complete this campaign are to be obtained from General Motors Service Parts Operations (GMSPO). Please refer to your "involved vehicles listing" before ordering requirements. Normal orders should be placed on a DRO = Daily Replenishment Order. In an emergency situation, parts should be ordered on a CSO = Customer Special Order.

Important: The service procedure contained in this campaign is different from the service procedure found in the appropriate Service Manual. As a result, the labor time allowance has been revised to correspond with this new service procedure.

Clutch Hydraulic System Fluid Change Procedure for 6 Speed Manual Transmission (ML6)

1. Loosen the clutch master cylinder reservoir cap 1/2 to one turn in order to assure ease of air entry.
2. Raise the vehicle.
3. From under the vehicle, detach the two clutch hose clips from the fuel line bracket on the side of the transmission.
4. Remove the small spring clip, which secures the hose end to the plastic clutch actuator elbow.
5. Pull the hose end out of the plastic elbow and catch the fluid as it drains out of the hose.
6. Lower the hose end sufficiently to assure complete draining of the hose.
7. When the flow stops, install the clip to the plastic clutch actuator elbow.
8. Insert the hose back into the plastic elbow.
9. Apply a load (3-4 lbs) on the hose in order to assure complete hose retention.
10. Reinstall the hose clips to the fuel bracket.

Important: Make sure that all clips are in place and that the clutch hose is not in contact with the exhaust pipe.

11. Lower the vehicle.
12. From under the hood, remove the clutch reservoir cap and extract the remaining fluid from the reservoir.
13. Fill the reservoir to "Max" fluid level line with known good fluid, GM P/N 12345347 (in Canada, use P/N 10953517).
14. Connect the hand vacuum pump (Kent-Moore J 23738-A or the equivalent) to the power steering bleeder adapter (Kent-Moore J 43485 or the equivalent).

Notice: Extended fluid contact to Kent-Moore tool J 43485 Adapter may cause deterioration to the material.

15. Place the adapter on top of the clutch master cylinder reservoir. While holding the adapter on top of the reservoir, pump the system to obtain 15-20 in. hg. of vacuum in the reservoir.

Important: The J 43485 Adapter is designed to sit on top of the clutch master cylinder reservoir. It is not intended to be inserted into the reservoir.

16. When the air bubbles can no longer be seen rising in the reservoir, release the vacuum and refill the reservoir to the "Max" level.

Important: The clutch pedal must be in the full up position in order to bleed the system.

17. Repeat Steps 13 through 16 until air bubbles no longer rise in the reservoir as the vacuum is applied (this typically requires 2-3 repetitions).
18. Install the new reservoir cap, GM P/N 88958857.
19. Move the clutch pedal to its full up and down position until the pedal returns to the full up position on its own (this typically requires 3-10 cycles).

Caution: The vehicle will move if started in gear before the clutch hydraulic system is refilled and operational. Start the vehicle the first time in Neutral to prevent accidents.

20. Verify full clutch release by starting the vehicle in Neutral gear position and attempting to engage a gear while holding the clutch pedal down. If the gear cannot be engaged easily, additional pedal stroking may be required. When all the air has been removed from the system, the clutch should be fully released when the pedal is 25mm (1 in) or less from the floor.
21. Verify the proper fluid level. Add additional fluid if needed.
22. Test drive the vehicle to ensure proper operation.
23. Install the GM Campaign Identification Label.

For US

Place a Campaign Identification Label on each vehicle corrected in accordance with the instructions outlined in this Product Campaign Bulletin. 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.

Put the Campaign Identification Label on a clean and dry surface of the radiator core support in an area that will be visible to people servicing the vehicle. When installing the Campaign Identification Label, be sure to pull the tab to allow the adhesion of the clear protective covering. Additional Campaign Identification Labels for US dealers can be obtained from Dealer Support Materials by calling 1-888-549-6152 (Monday-Friday, 8:00 am to 5:00 pm EST). Ask for Item Number S-1015 when ordering.

For Canada

Place a Campaign Identification Label on each vehicle corrected in accordance with the instructions outlined in this Product Campaign Bulletin. 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.

Put the Campaign Identification Label on a clean and dry surface of the radiator core support in an area that will be visible to people servicing the vehicle. Additional Campaign Identification Labels for Canadian dealers can be obtained from DGN by calling 1-800-668-5539 (Monday-Friday, 8:00 am to 5:00 pm EST). Ask for Item Number GMP91 when ordering.

Submit a Product Campaign Claim with the information indicated below.

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

Customers will be notified of this campaign on their vehicles by General Motors (see copy of customer letter included with this bulletin).

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, you must take the steps necessary to be sure the campaign correction has been made before selling or releasing the vehicle.

Dear General Motors Customer:

We want your experience owning your 2001 Chevrolet Silverado or GMC Sierra 2500HD or 3500 model truck to be better than any other you've had ... which is why we're writing.

We have learned that your 2001 Chevrolet Silverado or GMC Sierra 2500HD or 2500 model truck, equipped with an 8.1L V8 gasoline or 6.6L diesel engine, and a 6-speed manual transmission, may exhibit a condition in which the clutch fluid is contaminated by water that has been introduced through the reservoir cap. If the vehicle is operated at elevated transmission temperatures such as during heavy load hauling, this condition can cause loss of clutch pedal function until the clutch fluid cools below the fluid boiling point.

Your dealer will replace the clutch master cylinder fluid reservoir cap with a new cap, and drain and refill the reservoir with new hydraulic fluid. This service will be performed for you at no charge .

We recommend that you contact your <Division> dealer to arrange a service date so that your truck can be serviced as quickly as possible.

Presenting the attached card to your dealer will assist in making the necessary correction in the shortest possible time.

If you no longer own this vehicle, please check the appropriate box and provide new owner information, if available.

If you have any questions or need any assistance, just contact your dealer or the appropriate Customer Assistance Center at the number listed below:

Your dealer may provide you with shuttle service or some other form of courtesy transportation while your vehicle is at the dealership for this repair. Please refer to your Owner's Manual and your dealer for details on Courtesy Transportation.

We sincerely regret any inconvenience this causes you. Also, we want you to know that we will continue to do everything we can to ensure that you are completely satisfied with your 2001 Chevrolet Silverado or GMC Sierra 2500HD or 3500 and with <Division>.

General Motors Corporation

Enclosure