air brakes

It is not safe to drive a vehicle that has brake drums with cracks that are longer than ___of the width of the friction area

1/2

A slack adjusters free play needs to be adjusted if it is more than about ____ when you pull hard on it

1inch

The spring brakes used on the chambers In a straight truck will bring you to a stop when air pressure drops below___psi

20

If your truck or bus has dual parking control valves, you can use pressure from a separate tank to

Release the spring emergency/ parking brakes to move a short distance

How should you check that your service brakes are working properly

Park on level ground, wait until normal air pressure is reached, release the parking brakes as you and move forward slowly at 5 mph.

A straight truck or bus air brake system should not leak at the rate of more than ___psi per minute with the engine off and the brakes released

2

The air loss rate for a straight truck or bus with the engine off and and the brakes on should not be more than

3 psi in one minute

Total stopping distance for air brakes is longer than that for hydraulic brakes due to ___ distance

Brake lag

If the air compressor valve should develop a leak, what keeps the air in the tanks

The one way check valve

the safety valve reduces pressure at ___ psi

150

The supply pressure gauge shows how much pressure

Is in the air tanks

The ___ shows how much pressure is in the air tanks

Supply pressure gauge

To test air service brakes you should

Brake firmly while slowly moving forward