Heavy Duty Truck Systems - Chapter 31
UPDATED ACTUAL Exam Questions and
CORRECT Answers
Which of the following is the best practice when instructed to block the wheels on a
tractor/trailer combination? - CORRECT ANSWER - Place a pair of wedged wheel chocks
on one tractor drive axle and one trailer axle wheel.
What is the required amount of slack adjuster free travel on a properly adjusted, manual S-cam
brake? - CORRECT ANSWER - 3/8 to 5/8 inch
Which of the following foundation brake components are lubricated with chassis grease, either
for component life or as part of a lube job? - CORRECT ANSWER - S-cam bushings
A 161/2 inch brake drum specified to have a machine limit of 0.090 inch over and a maximum
dimension of 0.120 inch over is measured at 0.098 inch over at a brake overhaul. Technician A
says that the drum can be turned on a drum lathe, providing that the maximum dimension of
0.120 inch is observed. Technician B says that the drum can be legally returned to service
without being turned. Who is correct? - CORRECT ANSWER - Technician B only
A tandem axle trailer equipped with S-cam brakes has all four slack adjusters originally set with
a 6-inch dimension from the clevis pin to the camshaft. One slack adjuster is replaced, and
because of a different hole arrangement in the new slack adjuster, it is set at 61/2 inches. Which
of the following is more likely to result? - CORRECT ANSWER - One of the four wheels
will lock up ahead of the others under severe braking
When adjusting a manual slack adjuster on an S-cam foundation brake, Technician A says that
the lock collar should be retracted and the adjusting nut always rotated clockwise to decrease
free travel. Technician B says that free travel can be reduced only when the adjusting nut is
rotated counterclockwise. Who is correct? - CORRECT ANSWER - Neither A nor B
A set of brake linings has become glazed because of oil saturation by a failed wheel seal.
Technician A says that pressure washing the foundation brake components should be sufficient to
UPDATED ACTUAL Exam Questions and
CORRECT Answers
Which of the following is the best practice when instructed to block the wheels on a
tractor/trailer combination? - CORRECT ANSWER - Place a pair of wedged wheel chocks
on one tractor drive axle and one trailer axle wheel.
What is the required amount of slack adjuster free travel on a properly adjusted, manual S-cam
brake? - CORRECT ANSWER - 3/8 to 5/8 inch
Which of the following foundation brake components are lubricated with chassis grease, either
for component life or as part of a lube job? - CORRECT ANSWER - S-cam bushings
A 161/2 inch brake drum specified to have a machine limit of 0.090 inch over and a maximum
dimension of 0.120 inch over is measured at 0.098 inch over at a brake overhaul. Technician A
says that the drum can be turned on a drum lathe, providing that the maximum dimension of
0.120 inch is observed. Technician B says that the drum can be legally returned to service
without being turned. Who is correct? - CORRECT ANSWER - Technician B only
A tandem axle trailer equipped with S-cam brakes has all four slack adjusters originally set with
a 6-inch dimension from the clevis pin to the camshaft. One slack adjuster is replaced, and
because of a different hole arrangement in the new slack adjuster, it is set at 61/2 inches. Which
of the following is more likely to result? - CORRECT ANSWER - One of the four wheels
will lock up ahead of the others under severe braking
When adjusting a manual slack adjuster on an S-cam foundation brake, Technician A says that
the lock collar should be retracted and the adjusting nut always rotated clockwise to decrease
free travel. Technician B says that free travel can be reduced only when the adjusting nut is
rotated counterclockwise. Who is correct? - CORRECT ANSWER - Neither A nor B
A set of brake linings has become glazed because of oil saturation by a failed wheel seal.
Technician A says that pressure washing the foundation brake components should be sufficient to
