Air Brakes 1
Air Brakes 2
Air Brakes 3
Air Brakes 4
Air Brakes 5
100
What does the application pressure gauge show?
How much air pressure you are applying to the brakes.
100
BONUS DOUBLE POINTS!!
The trailer hand brake valve sends air pressure to the trailer brake system through the ______ line
Control
100
How often should the air reservoirs be drained?
Daily
100
Excessive use of the service brakes results in overheating which can lead to what?
Expansion of the brake drums and brake fade.
100
The air loss rate for a straight truck or bus with a full brake application and the engine off should not be more than how many psi?
3 psi per 1 minute
200
What is the purpose of a quick release valve in a Spring Parking Brake system?
It exhausts air quicker to apply spring parking brakes quicker.
200
Your truck has a dual air system and one of the systems loses its pressure. What will happen?
The other system will continue to operate and either the front or back brakes will not be fully operational.
200
The Trailer Air Supply Valve must shut off if pressure drops below what PSI?
45-20 PSI
200
What is the most common type of foundation brake found on heavy vehicles?
s-cam drum
200
In a dual air brake system, if you had primary brake failure which brakes would still operate?
Front axle brakes (steer axle)
300
Some air brake systems have an alcohol evaporator. What may happen if you don't keep the proper level of alcohol?
Ice may form in the air brake valves and cause brake failure
300
Parking or emergency brakes of trucks and buses can ONLY be legally held on by what type of pressure?
spring
300
BONUS DOUBLE POINTS WAHOO!
What is blended air?
Air taken from the primary and secondary circuit through a two way check valve.
300
Brake lag to the chambers is minimized by?
Installing a Relay Valve.
300
Camshaft Restrictor is a type of engine retarder. T or F?
F
400
If the trailer breaks away, the purpose of the Tractor Protection Valve is to?
Prevent Air Loss from the Tractor
400
What is the purpose of a Bobtail Proportioning System?
To help prevent wheel lock up and increase control
400
The Governor unloads the compressor at 130 psi, When does the Governor start loading?
105-110 or 80% of 130
400
Your truck or bus has a dual air brake system. If a low-pressure warning comes on for only one system, what should you do?
stop right away and safely park. continue only after the system is fixed
400
Spring type parking brakes are held in the released position by?
Air pressure
500
The Spring Brake Modulator Valve does what in the event of a Primary circuit failure?
Allows spring brakes to activate. (Under control)
500
If your truck has a properly functioning dual air brake system and minimum size air tanks, the air pressure should build up from 50 to 90 psi within how many minutes?
3
500
The driver must be able to see a low air pressure warning which comes on before pressure in the service air tanks fall below _____ psi?
60
500
My brake chamber has square air inlet ports. What does this mean?
It is a Long Stroke (LS) brake chamber.
500
To stop a vehicle, the energy of motion becomes
Heat in the brake linings and drums.