Amtrak Maintenance Level 2 (AMT-2) Practice Test

When an air compressor is not functioning properly, it often can’t sustain steady output, so you’ll see reduced or fluctuating system pressure. Leaks in hoses, fittings, or the air lines drain air and cause the pressure to drop, while a faulty pressure switch or governor can let the system cycle improperly, producing erratic pressure or oscillations. Because these issues produce the same symptom, the best first diagnostic step is to check for air leaks and inspect the control components. Start by looking for obvious leaks and listening for hissing, then verify the pressure switch and governor are operating correctly and inspect fittings for any signs of leakage. If there are leaks or the controls aren’t cycling properly, those are the likely causes; if those checks pass but pressure still isn’t stable, the compressor itself may be worn or damaged.