Section 5 Air brakes

Question 1

Air brakes are really three different braking systems?

Answer 1

Service brake
Parking brake
Emergency brake

Question 2

When air tank pressure rises to the cut out level around _______ psi the governor stops the compressor from pumping air?

Answer 2

125 psi

Question 3

When the tank pressure falls to the cut in pressure around _____ psi the governor allows the compressor to start pumping again?

Answer 3

100 psi

Question 4

A warning signal you can see must come on before the air pressure in the tank falls below______ psi?

Answer 4

60 psi

Question 5

Tractor and straight truck spring brakes will come fully on when air pressure drops to a range of ____ to _____ psi?

Answer 5

20 to 45 psi

Question 6

Before driving a vehicle with a dual air system, allow time for the air compressor to build up a minimum of ______ psi pressure in both primary and secondary air pressure gauges?

Answer 6

100 psi

Question 7

If a slack adjustor moves more than about ______ inch where the push rod attaches to it, it probably needs adjustment?

Answer 7

1 inch

Question 8

Brake drums or discs must not have cracks longer than _______ the width of the friction area?

Answer 8

One half

Question 9

When testing air leakage rate the loss rate should be less than _______PSI in 1 minute for single vehicles in less than ______ PSI and one minute for combination vehicles?

Answer 9

2 for single vehicles
Less than 3 psi in one minute for combination vehicles

Question 10

Perception Distance + Reaction Distance + Brake Lag Distance + Braking Distance=?

Answer 10

Total Stopping Distance