Power Brake Unit
- Run engine for 2 minutes. Turn off engine. Press brake pedal several times with normal pressure. Pedal height should be lowest when first pressed but should gradually become higher each time pedal is pressed.
- Step on brake pedal several times to ensure pedal height does not change. Press and hold brake pedal and start engine. Pedal should move slightly downward.
- With engine running, press and hold brake pedal and stop engine. Continue holding pedal down for 30 seconds. Pedal height should not change.
- If power brake unit does not test as specified, test check valve and vacuum hose. See CHECK VALVE (POWER BRAKE UNIT) . If check valve and vacuum hose are okay, replace power brake unit.