The following inspections will help locate master cylinder malfunctions. Use the Hydraulic Brake Diagnostic System Check in order to help isolate the problem if the problem is not found through the following tests:

1. Inspect for a cracked master cylinder casting.
2. Inspect for brake fluid around the master cylinder. A leak is present if there is at least one drop of fluid. A damp condition is normal.
3. Inspect for binding pedal linkage.
4. If the pedal linkage and the pushrod length are correct, remove the master cylinder reservoir cap. Inspect for a distorted or swollen diaphragm.
5. If a swollen diaphragm is found, substandard or contaminated brake fluid is the probable cause. If the fluid if contaminated, use the following procedure:

•	Flush the hydraulic brake system. Refer to Hydraulic Brake System Flushing .

•	Disassemble and clean the serviceable components.

•	Replace all of the rubber and non-serviceable components.

•	Flush the hydraulic brake system again. Refer to Hydraulic Brake System Flushing .