GM Service Manual Online
For 1990-2009 cars only

Causes

Correction

Leaking brake pipe/connection

Locate and fix the brake pipe/connection.

Leaking caliper piston seal

Replace the caliper piston seal.

Leaking master cylinder (internally)

Repair/replace the master cylinder.

Leaking rear wheel cylinder

Repair/replace the rear wheel cylinder.

Leaking proportioning valve

Replace the proportioning valve.

Restricted passage in vacuum booster

Replace the vacuum booster.

Damaged vacuum booster

Replace the vacuum booster.

Restricted brake fluid passage

Locate and fix the brake fluid passage restriction.

Improper rear brake adjustment

Adjust the rear brake linings.