Stop point
Direct answer
Stop when air pressure will not build, warnings stay active, leaks are present, or the inspection test fails. Use the current state CDL manual, company policy, and a qualified mechanic for live vehicle defects.
How to use this answer
Read the answer once, then prove it by choosing an answer in a practice question before looking at the explanation. If the miss repeats, tag the domain as CDL air brakes and drill a smaller set before returning to mixed practice.