1. The governor controls when the air compressor will pump air into the air storage tanks. When air tank pressure rises to the "cut-out" level the governor stops the compressor from pumping air. What is the "cut-out" pressure?
25 psi 90 psi 125 psi 150 psi
2. A safety relief valve is installed in the first tank the air compressor pumps air to. The safety valve protects the tank and the rest of the system from too much pressure. The valve is usually set to open at what pressure?
60 psi 90 psi 100 psi 150 psi
3. The most common type of foundation brakes are?
s-cam drum brakes wedge brakes disc brakes d-cam drum brakes
4. A low pressure warning signal is required on vehicles with air brakes. A warning signal you can see must come on before the air pressure in the tanks falls below what pressure?
40 psi 60 psi 90 psi 100 psi
5. Tractor and straight truck spring brakes will come fully on when air pressure drops to a range of?
20-45 psi 60-90 psi 100-125 psi 125-150 psi
6. Truck tractors with air brakes built on or after what date are required to be equipped with antilock brakes?
March 1, 1977 March 1, 1987 March 1, 1997 March 1, 2007
7. Brake drums must not have cracks longer than what amount of the friction area?
one half the length one forth the width one forth the length one half the width
8. When the engine is at operating rpms in duel air systems the pressure should build from 85-100 psi within how many seconds
30 45 90 180
9. Pumping by the air compressor should start at about 100 psi and stop at about what pressure
110 psi 125 psi 150 psi 175 psi
10. The air brake lag distance at 55 mph on dry pavement adds about how many feet to stopping distance?
16 32 92 135
11. All trucks, truck tractors, and buses must be equipped with?
emergency brakes only parking brakes only emergency brakes and parking brakes service brakes only
12. A device that drops a mechanical arm into your view when the pressure in the system drops below 60 psi?
visor wig wag wiper wig
13. The application pressure gauge shows how much air pressure
you are applying to the brakes you have in your air tanks is leaking you are applying to the safety valve
14. The safety valve is installed
in the first tank the air compressor pumps air to in the second tank the air compressor pumps air to on the service line on the emergency line
15. Some vehicles, such as buses, have a separate air tank which can be used to release the spring brakes. This is so you can
drive 50 more miles keep on driving any amount of miles drive to the nearest service station move the vehicle in an emergency
16. Trailers will have yellow ABS malfunction lamps on
the left side, either on the front or rear corner the right side, either on the front or rear corner the rear if the trailer the front of the trailer
17. When the low air pressure warning light and buzzer first come on
drive to the nearest service station bring vehicle to a safe stop right away pull the emergency brake pump the brakes
18. The braking power of spring brakes depends on
the weight of the load good tires the driver the brakes being in adjustment
19. Before driving a vehicle with dual air system, allow time for the air compressor to build up a minimum of ____ in both the primary and secondary systems
60 psi 100 psi 125 psi 150 psi
20. With controlled braking
you lock the wheels you apply the brakes as hard as you can without locking the wheels you apply the emergency brakes you apply the parking brake
