Coolant System Pressure Testing

• Always test with the engine warm
• Test pressure 1.35 bar

Note: It may be necessary to test the engine cold if a very small leak is suspected. With a warm engine, it is possible for a small leak in a hot part of the engine to evaporate before traces of it can be detected. Pressurising the engine cold and leaving it for a period with paper or a dry floor underneath it will often find such a leak.

• Pressure relief valve in cap opens at 1.2 to .13 bar
• Pressure testing an old cap may be destructive - the valve may fail to close again after the test.