Substandard or Contaminated Brake Fluid
Important:
• Use only Delco Supreme 11® Brake Fluid, GM P/N 1052535
(Canadian P/N 992667), or equivalent DOT 3 fluid. • Do not use power steering or transaxle fluid in the brake system. • Do not reuse brake fluid collected during system bleeding. • Always store brake fluid in a closed container. • Reseal brake fluid containers immediately after use. • Do not use brake fluid left in an open container or an improperly
sealed container because it absorbs moisture or can become contaminated. • The following fluids may cause the brake fluid to boil or the
rubber components in the hydraulic system to deteriorate: - Water - A silicone based fluid - A petroleum based fluid - Mineral oil • The following conditions provide evidence that the rubber components
have deteriorated: - Swollen primary piston cups - Swollen piston cups on the drum brake wheel cylinders - Substandard or contaminated brake diaphragm - Substandard or contaminated master cylinder cover diaphragm • If deterioration of rubber is evident, complete the following
procedure: 1. Disassemble all of the hydraulic parts. 2. Wash all of the parts with alcohol. 3. Dry these parts with non-lubricated compressed air before assembly
in order to keep alcohol out of the system. • Replace all of the rubber parts in the system, including the hoses. • Inspect the brake linings for fluid. If excessive fluid is found on the brake linings, replace the brake
linings. • If the master cylinder piston seals are satisfactory, inspect
for the following conditions: - Leaking - Excessive heat • If these conditions are not found, flush the hydraulic brake system.
Refer to
Hydraulic Brake System Flushing
.
