Service Procedure for Brake Pressure Modulator Valves Equipped with 8 Degree Accumulator Plates

The purpose of this bulletin is to identify the two different accumulator plates that were used for 2000 Saturn S-Series vehicles equipped with ABS. Early production vehicles were built with an 8° accumulator plate. Later production vehicles were built with a 0° accumulator plate.

Notice: Due to the different accumulator plates, separate brake pipe configurations were also used. It is extremely important that the proper degree accumulator plate be matched with the proper degree brake pipe. If incorrectly matched, cross threading, leaks, and stress cracks of brake pipes may occur.

Accumulator plates can be identified by the numbers stamped on the top side of the plates:

Notice: Only one BPMV assembly is available for service and it is mounted to a 0° accumulator plate. When BPMV replacement is required, P/N 21013424 should be ordered for vehicles equipped with both 8° and 0° accumulator plates. Refer to "Part Requirements" at the end of this bulletin for more part information.

Important: If servicing a vehicle built after and including VIN YZ168355, disregard this bulletin and refer to the service procedure outlined in the Antilock Brakes System section of the 2000 S-Series Brakes Service Manual.

2000 model year Saturn S-Series vehicles equipped with ABS and built before VIN YZ16835 contain a brake pressure modulator valve (BPMV) mounted on an 8° accumulator plate.

If a BPMV requires replacement on a vehicle built with an 8° accumulator plate, P/N 21013424 should be ordered. (The part received will contain a BPMV mounted to a 0° accumulator plate.)

Notice: Before installing a new BPMV (P/N 21013424) on a vehicle built before VIN YZ168355, it will be necessary to transfer the accumulator plate from the old BPMV. Transferring the accumulator plate ensures that the proper degree accumulator plate is matched with the proper degree brake pipe. It is critical that 8° vehicles retain an 8° accumulator plate, or brake pipes will not align.

Important: The procedure for removing and transferring accumulator plates applies to vehicles with 8° accumulator plates only.

The procedure outlined below applies to vehicles with 8° accumulator plates only. If servicing a vehicle with a 0° accumulator plate, disregard the procedure below and refer to the service procedures in the Antilock Brakes System section of the 2000 S-Series Brakes Service Manual.

Notice: Due to the different accumulator plates, separate brake pipe configurations were also used. It is extremely important that proper degree accumulator plates be matched with proper degree brake pipes. If incorrectly matched, cross threading, leaks, and stress cracks of brake pipes may occur.

Notice: Thoroughly clean ABS housing and brake pipes prior to removing from vehicle.

1. Remove ABS assembly from vehicle, and separate brake pressure modulator valve (BPMV) from electronic brake traction control module (EBTCM). (Refer to "Electronic Brake and Traction Control Module [EBTCM] and Brake Pressure Modulator Valve [BPMV]" removal procedure in the Antilock Brakes System section of the 2000 S-Series Brakes Service Manual.)
2. Turn BPMV removed from vehicle upside down on a clean workbench. Remove Torx® screws and retain for future use.




Notice: Once accumulator plate is removed from brake pressure modulator valve (BPMV), DO NOT turn the BPMV over. If turned over, accumulator springs, pistons, and check valves can fall out of assembly. Avoid getting dirt and debris into the BPMV.

3. Remove 8° accumulator plate from BPMV.
4. Turn new BPMV (P/N 21013424) upside down on a clean workbench. Remove Torx® screws and retain for future use.




Important: Retain new 0° accumulator plate for future use. New 0° accumulator plate must be re-installed onto inoperative BPMV for parts return and evaluation purposes.

5. Remove 0° accumulator plate from new BPMV.
6. If accumulator check valves, pistons, and springs fell out of the BPMV, ensure they are in the proper location before proceeding to the next step.




Notice: If the 8° accumulator plate removed from the vehicle is damaged, a new one is available separately for service (P/N 21013425).

Important: Accumulator plates (1) can be identified by the numbers stamped on the top side of the plates at location (2):

- 8° accumulator plates are stamped 18026121
- 0° accumulator plates are stamped 18043620
7. Install 8° accumulator plate removed from vehicle onto new BPMV.
8. Align screw holes. If all eight holes do not align, accumulator plate is incorrectly installed.
9. Install and hand start screws.



10. Torque screws following torque pattern shown.

Tighten
Tighten screws to: 4-6 N·m (35-55 lb in)

11. Repeat steps 7 through 10 to install new 0° accumulator plate onto inoperative BPMV. New 0° accumulator plate must be re-installed for parts return and evaluation purposes.
12. Connect new BPMV to EBTCM and install complete ABS assembly into vehicle. (Refer to "Electronic Brake and Traction Control Module [EBTCM] and Brake Pressure Modulator Valve [BPMV]" installation procedure in the Antilock Brakes System section of the 2000 S-Series Brakes Service Manual.)

To receive credit for this repair during the warranty coverage period, submit a claim through the Saturn Retailer System for H2518 (Modulator, (ABS) - Replace).