Operation CHARM: Car repair manuals for everyone.

Brake Fluid Leaks

Use the following procedure in order to test for brake problems that may be caused by fluid leaks:

1. Start the engine and run the engine at idle speed.
2. Shift the transmission into neutral.
3. Maintain constant foot pressure on the brake pedal. If the pedal slowly sinks to the floor, the hydraulic system may have internal leakage, external leakage or improperly adjusted components.
4. Perform a visual inspection of the hydraulic system.
5. Check the fluid level of the master cylinder.
^ A slightly low fluid level in either reservoir can result from normal wear of the front brake lining.
^ An abnormally low fluid level indicates a leak in the hydraulic system.
^ Even with a high fluid level there may be small leaks. Refer to Master Cylinder Reservoir Filling.

If you find no external leaks, internal leakage may be the cause. The master cylinder must be disassembled in order to diagnose internal leakage.