How to do an air brake leak test on a semi truck

An air brake leak test is one of those checks drivers say they know, then rush when the clock is tight. I started taking it slower after a tractor that looked fine in the yard started dropping pressure at a dock door. Since then I treat the leak test like a real shop note, not just a CDL memory item. I build full pressure first and let the governor cut out. Then I set the parking brakes, shut the…