HEAVY TRUCK BRAKES MICHIGAN TEST PAPER
QUESTIONS AND ANSWERS RATED A+
✔✔Technician A says that a trailer service brake signal is always sourced from the
tractor primary circuit. Technician B says that a trailer service signal can only pass
through a tractor protection valve when it is in its ON state. Who is correct? - ✔✔Tech B
✔✔Technician A says that most current highway tractors use a 3-line TP valve.
Technician B says that a 2-line TP valve will remain OFF until the trailer air supply dash
button is depressed. Who is correct? - ✔✔Tech B
✔✔How man anchor pins are used for a pair of S-cam actuated brake shoes? - ✔✔Two
✔✔What term is used to measure the aggressiveness of friction linings? - ✔✔The
coefficient of friction
✔✔In current practices in a truck service facilities, when should a truck brake drum be
machined? - ✔✔Only when new
✔✔What is the maximum permitted service oversize dimension permitted for a standard
16.5 brake drum be machined? - ✔✔0.120-inch
✔✔When under severe braking the wheels of a trailer lock causing it to spin around
while the tractor remains in a straight ahead position, the condition is known as? -
✔✔Trailer swing
✔✔What is the function of the compressor on a truck air brake system? - ✔✔Compress
ambient air
✔✔Aerodynamic tractor trailer rigs should have what effect on vehicle braking? -
✔✔Make the rig more difficult to stop
QUESTIONS AND ANSWERS RATED A+
✔✔Technician A says that a trailer service brake signal is always sourced from the
tractor primary circuit. Technician B says that a trailer service signal can only pass
through a tractor protection valve when it is in its ON state. Who is correct? - ✔✔Tech B
✔✔Technician A says that most current highway tractors use a 3-line TP valve.
Technician B says that a 2-line TP valve will remain OFF until the trailer air supply dash
button is depressed. Who is correct? - ✔✔Tech B
✔✔How man anchor pins are used for a pair of S-cam actuated brake shoes? - ✔✔Two
✔✔What term is used to measure the aggressiveness of friction linings? - ✔✔The
coefficient of friction
✔✔In current practices in a truck service facilities, when should a truck brake drum be
machined? - ✔✔Only when new
✔✔What is the maximum permitted service oversize dimension permitted for a standard
16.5 brake drum be machined? - ✔✔0.120-inch
✔✔When under severe braking the wheels of a trailer lock causing it to spin around
while the tractor remains in a straight ahead position, the condition is known as? -
✔✔Trailer swing
✔✔What is the function of the compressor on a truck air brake system? - ✔✔Compress
ambient air
✔✔Aerodynamic tractor trailer rigs should have what effect on vehicle braking? -
✔✔Make the rig more difficult to stop
