Air Brakes Test 2

1. Air loss in a straight truck or bus should not be more than ____ with the engine off and the brakes on.
1 psi in 30 seconds
1 psi in one minute
2 psi in 45 seconds
3 psi in one minute

2. To make an emergency stop with air brakes, using the stab braking method, you should:
Pump the brake pedal rapidly and lightly.
Brake hard until the wheels lock, and then get off the brakes for as much time as the wheels were locked.
Brake as hard as you can, get off the brakes when the wheels lock, get back on the brakes when the wheels start rolling again.
Press hard on the brake pedal and apply full hand valve until you stop.

3. You should know that your brakes are fading when:
Pressure on the brake pedal is released and speed increases.
You have to push harder on the brake pedal to control your speed on a downgrade.
The brake feels spongy when pressure is applied.
Less pressure is needed on the brake pedal for each stop.

4. To check the free play of manual slack adjusters on s-cam brakes you should:
Park on level ground, chock the wheels, and release the parking brakes.
Stop on level ground and apply the parking brakes.
Park on level ground and drain off air pressure before adjusting.
Park on a slight grade, release the parking brake, apply the service brakes, and check for vehicle movement.

5. If the air compressor should develop a leak, what keeps the air in the tanks?
The tractor protection valve
The emergency relay valve
The one way check valve
The air compressor