Why is a static leakage test, checking how much pressure drops over a period with the engine off and brakes off, part of the air brake check?

Pick an answer

1. It has no bearing on braking; it only checks the horn circuit
2. It reveals leaks in the system that could reduce reliable braking over time
3. It is used only to test the air conditioning system
4. It replaces the need to check the low air pressure warning separately, though that is not correct

Correct!

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