Substandard or Contaminated Brake Fluid

If the brake fluid contains improper fluid, water, or other contaminates, the brake fluid may boil or may deteriorate rubber components in the hydraulic brake system.
Evidence of rubber deterioration occurs in the following areas:
- Swollen master cylinder piston seals
- Swelling of the wheel cylinder boots
- Swelling of caliper boots
- Swelling of the master cylinder reservoir diaphragm

If rubber deterioration is found, replace all rubber parts, including the hoses, in the brake system.
Check for brake fluid on the brake linings. Replace the brake linings that are contaminated with brake fluid.
If the brake fluid is contaminated and the master cylinder piston seals are good, check for leaks and excessive heat conditions. If no leaks or excessive heat conditions are found, flush the brake system.