Non-Pressure Leaks

Low brake fluid level in the brake master cylinder reservoir may be caused by the following non-pressure external leaks:
Type 1. An external leak may exist at the brake master cylinder filler cap due to improper position of the cap, cap gasket, or gasket deterioration.
Type 2. An external leak may exist at the brake master cylinder mounting flange due to internal seal failure. Repair or replace the brake master cylinder.
Type 3. An external leak may exist at the base of the brake master cylinder reservoir due to deteriorated reservoir mounting seals. Repair or replace the brake master cylinder.