Fourth Servo Overhaul

WARNING: This page is about a different car, the 2007 Cadillac DTS. However, it is still accessible from the selected car via links, so may be relevant.

Fig 1: View Of 4th Servo Piston Components

Courtesy of GENERAL MOTORS CORP.

Remove the following parts:
- The 4th servo piston seals (532, 525)
- The snap ring (531)
- The apply pin (527)
- The spring and retainer assembly (533)

Fig 2: 4th Servo Piston Components Inspection Areas

Courtesy of GENERAL MOTORS CORP.

Inspect the following parts:
- The 4th servo piston (529) for cracks
- The apply pin (527) for damage
- The spring and retainer assembly (533) for damage
- The servo cover (524) for damage

Fig 3: Identifying 4th Servo Piston Components

Courtesy of GENERAL MOTORS CORP.

Install the following parts:
- The new piston seal (532) onto the 4th servo piston (529)
- The apply pin (527)
- The spring retainer (533) into the 4th servo piston (529)
- Attach the snap ring (531) to the apply pin (527).

Fig 4: Identifying 4th Servo Piston Assembly And Cover

Courtesy of GENERAL MOTORS CORP.

Install the 4th servo piston assembly (529) and the spring (533) into the 4th servo cover (524).
Apply pipe thread sealant GM P/N 12346004 to bolt threads before installation.
Install the 4th servo piston and cover assembly into the case.

Fig 5: Installing 4th Servo Cover Bolts While Compressing Piston

Courtesy of GENERAL MOTORS CORP.

NOTE: Refer to Fastener Notice in Cautions and Notices.

Install the 4th servo cover bolts into the case. Hand tighten the bolts while holding the piston compressed.
Tighten: Tighten the bolts in a star pattern to 8-14 N.m (6-10 lb ft).