ASE T5 Brakes: Comprehensive
Diagnosis, Service, and Repair
Systems (2026 Latest Update
1. The truck with the air suspension system shown above leans to the right. Technician
A says that valveX could be the cause. Technician B says that valve Y
could be the cause. Who is right?
A. Technician A only
B. Technician B only
C. Both A and B
D. Neither A or B - Answer--1. The correct answer is C, both technicians are right.
Height control valves can fail in either direction-that is, by controlling the height at too
great a
level or at too low a level. If the truck leans, the cause can be either too great a height
on one side or too low a height on the other. Until the technician knows that
one side is too high or the other too low, he must assume that either valve might be
malfunctioning.
4. The drive axles on a truck with a walking beam suspension are out of alignment in a
manner that is causing vehicle tire wear and steering instability.
Technician A says the cause could be that the torque rods are too long or too short.
Technician B says the cause could be worn walking beam bushings. Who is
right?
A. Technician A only
B. Technician B only
C. Both A and B
D. Neither A or B - Answer--4. The correct answer is B. The beam bushings maintain
horizontal alignment of the axles, especially on turns. When bushings are worn, the
beam on either
,side can move forward or backward, turning the axles in relation to the frame and
causing the type of misalignment that causes tire wear and steering problems.
2. The driver of a truck says that he hears a clattering noise from the front axle when
driving on a rough road. Technician A says the cause could be worn shock absorber
mounting bushings. Technician B says the cause could be worn shackle bushings. Who
is right?
A. Technician A only
B. Technician B only
C. Both A and B
D. Neither A or B - Answer--2. The correct answer is C, both technicians are right.
Either a worn shackle bushing or worn shock bushing can cause noise due to looseness
when the truck hits a good bump. If there is clearance between the rubber bushing and
mounting bolt, or if the rubber
bushing has worn very thin, elongated or even broken and fallen out, the result will be a
clattering noise as the motion of the suspension repeatedly takes up the
clearance first in one direction and then in the other.
5. The driver of a truck says that it is too hard to steer and that the steering wheel return
is too fast. Which of these is the most likely cause?
A. too much negative caster
B. too much positive caster
C. too much negative camber
D. too much positive camber - Answer--5. The correct answer is B. Caster action is the
most critical suspension alignment specification in terms of affecting steering wheel
return to the center. Caster
actually lifts the truck as the wheel is turned in either direction; when the driver allows
the wheel to return to center, the weight of the truck actually forces the steering system
to that position. When the caster setting is too high, the weight of the truck exerts too
much force in centering the steering and creates the symptoms
noted.
3. The driver of a truck that has just had its front springs and hangers replaced says that
it is hard to keep the steering wheel in a straight-ahead position. Technician A says the
cause could be that the caster shims were installed backwards. Technician B says the
cause could be that the wrong spring hangers were installed. Who is right?
A. Technician A only
B. Technician B only
C. Both A and B
, D. Neither A or B - Answer--3. The correct answer is A. Correct caster is critically
important in keeping tires at the right angle and enabling the steering system to
maintain directional
stability. Since the caster shims would have to be removed for this work to be done, it's
quite logical to assume they might have been installed backwards, which would create
the critically incorrect caster setting that would make the truck wander severely.
6. A steering gear binds when turning to the left after it has been adjusted. The most
likely cause is that the:
A. worm bearing preload was set too high
B. steering shaft U-joints are sticking
C. gearbox was not centered when the lash was adjusted
D. recirculating ball nut thrust adjustment is off - Answer--6. The correct answer is A.
Excessive worm bearing preload would show up as binding as the steering was turned
to one extreme and the friction became excessive due to the combination of normal
load and too much preload. B is not the answer because sticking U-joints should be
apparent and cause rough rotation
of the wheel at all steering angles. If either lash or ball nut thrust adjustment was
incorrect, the box would either bind at the center or be too loose at the extremes
of travel.
7. Which of these is most likely to cause steering wheel shimmy?
A. too much positive caster
B. out-of-balance wheels
C. air in the power steering system
D. low tire pressure - Answer--7. The correct answer is B. Out-of-balance wheels cause
a high frequency vibration, which shows up in the wheel as shimmy. A is not the answer
because caster shows up as too much self-centering action (hard steering). Air in the
power steering system causes constantly or intermittently hard steering (lack of
hydraulic force). Low tire pressures generally do not cause an uneven force on the
steering system, but rather poor tread contact with the road and vague steering or hard
steering.
8. Technician A says that steering columns are collapsible to prevent the column from
causing serious injury to the driver during a collision. Technician B says that when a
steering column has been collapsed, the entire column must be replaced. Who is right?
A. Technician A only
B. Technician B only
C. Both A and B
Diagnosis, Service, and Repair
Systems (2026 Latest Update
1. The truck with the air suspension system shown above leans to the right. Technician
A says that valveX could be the cause. Technician B says that valve Y
could be the cause. Who is right?
A. Technician A only
B. Technician B only
C. Both A and B
D. Neither A or B - Answer--1. The correct answer is C, both technicians are right.
Height control valves can fail in either direction-that is, by controlling the height at too
great a
level or at too low a level. If the truck leans, the cause can be either too great a height
on one side or too low a height on the other. Until the technician knows that
one side is too high or the other too low, he must assume that either valve might be
malfunctioning.
4. The drive axles on a truck with a walking beam suspension are out of alignment in a
manner that is causing vehicle tire wear and steering instability.
Technician A says the cause could be that the torque rods are too long or too short.
Technician B says the cause could be worn walking beam bushings. Who is
right?
A. Technician A only
B. Technician B only
C. Both A and B
D. Neither A or B - Answer--4. The correct answer is B. The beam bushings maintain
horizontal alignment of the axles, especially on turns. When bushings are worn, the
beam on either
,side can move forward or backward, turning the axles in relation to the frame and
causing the type of misalignment that causes tire wear and steering problems.
2. The driver of a truck says that he hears a clattering noise from the front axle when
driving on a rough road. Technician A says the cause could be worn shock absorber
mounting bushings. Technician B says the cause could be worn shackle bushings. Who
is right?
A. Technician A only
B. Technician B only
C. Both A and B
D. Neither A or B - Answer--2. The correct answer is C, both technicians are right.
Either a worn shackle bushing or worn shock bushing can cause noise due to looseness
when the truck hits a good bump. If there is clearance between the rubber bushing and
mounting bolt, or if the rubber
bushing has worn very thin, elongated or even broken and fallen out, the result will be a
clattering noise as the motion of the suspension repeatedly takes up the
clearance first in one direction and then in the other.
5. The driver of a truck says that it is too hard to steer and that the steering wheel return
is too fast. Which of these is the most likely cause?
A. too much negative caster
B. too much positive caster
C. too much negative camber
D. too much positive camber - Answer--5. The correct answer is B. Caster action is the
most critical suspension alignment specification in terms of affecting steering wheel
return to the center. Caster
actually lifts the truck as the wheel is turned in either direction; when the driver allows
the wheel to return to center, the weight of the truck actually forces the steering system
to that position. When the caster setting is too high, the weight of the truck exerts too
much force in centering the steering and creates the symptoms
noted.
3. The driver of a truck that has just had its front springs and hangers replaced says that
it is hard to keep the steering wheel in a straight-ahead position. Technician A says the
cause could be that the caster shims were installed backwards. Technician B says the
cause could be that the wrong spring hangers were installed. Who is right?
A. Technician A only
B. Technician B only
C. Both A and B
, D. Neither A or B - Answer--3. The correct answer is A. Correct caster is critically
important in keeping tires at the right angle and enabling the steering system to
maintain directional
stability. Since the caster shims would have to be removed for this work to be done, it's
quite logical to assume they might have been installed backwards, which would create
the critically incorrect caster setting that would make the truck wander severely.
6. A steering gear binds when turning to the left after it has been adjusted. The most
likely cause is that the:
A. worm bearing preload was set too high
B. steering shaft U-joints are sticking
C. gearbox was not centered when the lash was adjusted
D. recirculating ball nut thrust adjustment is off - Answer--6. The correct answer is A.
Excessive worm bearing preload would show up as binding as the steering was turned
to one extreme and the friction became excessive due to the combination of normal
load and too much preload. B is not the answer because sticking U-joints should be
apparent and cause rough rotation
of the wheel at all steering angles. If either lash or ball nut thrust adjustment was
incorrect, the box would either bind at the center or be too loose at the extremes
of travel.
7. Which of these is most likely to cause steering wheel shimmy?
A. too much positive caster
B. out-of-balance wheels
C. air in the power steering system
D. low tire pressure - Answer--7. The correct answer is B. Out-of-balance wheels cause
a high frequency vibration, which shows up in the wheel as shimmy. A is not the answer
because caster shows up as too much self-centering action (hard steering). Air in the
power steering system causes constantly or intermittently hard steering (lack of
hydraulic force). Low tire pressures generally do not cause an uneven force on the
steering system, but rather poor tread contact with the road and vague steering or hard
steering.
8. Technician A says that steering columns are collapsible to prevent the column from
causing serious injury to the driver during a collision. Technician B says that when a
steering column has been collapsed, the entire column must be replaced. Who is right?
A. Technician A only
B. Technician B only
C. Both A and B
