6. The safety valve is set automatically when pressure is:
7. Your truck has a dual air system and one of the systems loses its pressure. What will happen?
Either the front or back brake will not be fully operational.
8. Parking or emergency brakes of trucks and buses can be legally held on by ___ pressure.
9. If your truck or bus has dual parking control valves, you can pressure from a separate tank to:
Release the spring emergency/parking brakes to move a short distance.
10. If your truck has a properly functioning dual air brake system and minimum size air tanks the air pressure should build up from 85 to 100 psi within how many seconds?