Functional Test
- Start engine. Turn ignition off. Depress brake pedal several times. Depress pedal firmly and hold for 15 seconds. If pedal sinks, master cylinder, brakeline or caliper piston is faulty.
- Start engine with pedal depressed. If pedal sinks slightly, vacuum unit is working properly. If pedal height does not vary, power brake unit or check valve is faulty. Replace as necessary.