Air Tightness Check
- Start engine and run for 1-2 minutes, then turn engine off. Depress brake pedal several times slowly. If pedal goes down farthest on first time, but gradually rises after second or third time, power brake unit is airtight.
- With engine stopped, depress brake pedal several times using normal pressure. Pedal should be low when first depressed. On consecutive applications, pedal height should gradually rise. If pedal height does not increase, check for air leaks.