ASE T4 BRAKES EXAM QUESTIONS AND
ANSWERS 100% PASS 2026 UPDATE.
2. The Driver Vehicle Inspection Report DVIR should be submitted :
A. according to the vehicle maintenance schedule
B. when a failure occurs
C. weekly
D. daily - ANS The correct answer is D. Federal Motor Vehicle Safety Standards ( FMVSS )
require the driver to submit a DVIR to their motor carrier or owner at the end of each day . The
DVIR is used to identify defects or deficiencies that would result in a mechanical breakdown or
effect the safe operation of a vehicle Once a driver submits the DVIR , a motor carrier or its
agent must investigate and repair the defect or deficiency .
3. Which of the following cannot cause a drum on an air - braked vehicle to overheat ?
A. an over - tightened brake adjuster at that wheel
B. under - adjusted brake ( s ) elsewhere on the vehicle
C. too - high governor cut - out pressure
D. driving downhill in too high a gear. - ANS 3. The correct answer is C. The governor controls
the air compressor output by unloading or cycling it . It has no direct effect on the mechanical
brake parts . While the pressure setting is important to maintain air brake system pressure
within acceptable limits , an incorrect setting will not cause the drum on an air - braked vehicle
to overheat . All other choices given , however , will cause overheating problems .
4. All the brakes drag on a truck with hydraulic brakes . Which of the following could be the
cause ? A. air in the hydraulic system
B. too high a vacuum supply to the power brake booster
1 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
,C. a leaking secondary cup in the master cylinder
D. no brake pedal free travel - ANS 4. The correct answer is D. Only a brake pedal with no free
travel will cause all of the brakes to drag . Answer A - air in the hydraulic system , will cause a
spongy pedal , while answer B - too high a vacuum to the power booster , won't affect brake
drag at all . Answer C , a leaking secondary cup in the master cylinder , could increase pedal
travel , but won't cause the brakes to drag .
5. Which of the following could cause a pulsating brake pedal on a truck with hydraulic brakes ?
A. zero brake pedal free travel
B. glazed linings
C. an out - of - round brake drum
D. a frozen wheel cylinder piston. - ANS 5. The correct answer is C. Of the choices given , only
an out - of - round brake drum can cause pulsation in a hydrau lic brake system . Answer A , zero
brake pedal free travel , will cause a dragging brake condition , but not pulsation . Answer B ,
glazed linings , will affect stopping performance and noise , and answer D , a frozen wheel
cylinder , will de grade stopping performance , but will not cause pulsation.
6. Air pressure gauges change an air pressure signal into an electronic voltage signal using which
of the following components ?
A. inductor
B. capacitor
C. transducer
D. regulator - ANS 6. The correct answer is C. An element inside an air pressure transducer
responds to air pressure increase or decrease, and the transducer converts that pressure
differentiation into a voltage signal, which is displayed in a proportionate reading on the dash
gauge.
7. Technician A says that linings worn too thin on an air - braked vehicle can cause the S -
camshaft to roll over . Technician B says this condition can cause excess brake pedal travel . Who
is right ?
A. Technician A only
B. Technician B only
C. Both A and B
2 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
, D. Neither A or B - ANS 7. The correct answer is A. The brake adjuster is connected to a shaft
that runs perpendicular to the plane formed by the pushrod and slack adjuster. As the pushrod
is extended, the shaft rotates. The shaft, in turn, is connected to an S-shaped cam between the
brake shoes. As the shaft rotates, so does the cam. The brake shoes are forced apart and against
the brake drum, creating the friction needed to slow the vehicle. Thin brake linings can allow
the S-cam to roll over, but will not affect brake pedal travel.
8. Spring brakes on an air - braked vehicle must be able to hold the vehicle facing uphill or
downhill on what percent grade ?
A. 10 %
B. 20 %
C. 30 %
D. 40 % - ANS 8. The correct answer is B. Per Federal Motor Vehicle Safety Standard (FMVSS)
121, the parking brakes must be able to hold a vehicle, loaded to its gross weight rating,
stationary on a smooth, dry, concrete roadway, facing uphill or downhill on a 20% grade. In the
emergency mode, the parking brakes must be able to exert a retarding force equal to 28% of the
gross axle rating.
9. The driver of a truck with hydraulic brakes says the pedal reserve is too low . Technician A
says the brakes could be out of adjustment Technician B says one brake system may have failed .
Who is right ?
A. Technician A only
B. Technician B only
C. Both A and B
D. Neither A or B - ANS 9. The correct answer is C, both Technicians are right.
Either condition will cause the driver to notice a low pedal reserve.
10. The parking brakes fail to apply on a truck with air brakes . Technician A says this could be
caused by low air pressure in the spring brake chamber . Techni cian B says this could be caused
by a ruptured spring brake diaphragm . Who is right ?
A. Technician A only
B. Technician B only
C. Both A and B
3 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
ANSWERS 100% PASS 2026 UPDATE.
2. The Driver Vehicle Inspection Report DVIR should be submitted :
A. according to the vehicle maintenance schedule
B. when a failure occurs
C. weekly
D. daily - ANS The correct answer is D. Federal Motor Vehicle Safety Standards ( FMVSS )
require the driver to submit a DVIR to their motor carrier or owner at the end of each day . The
DVIR is used to identify defects or deficiencies that would result in a mechanical breakdown or
effect the safe operation of a vehicle Once a driver submits the DVIR , a motor carrier or its
agent must investigate and repair the defect or deficiency .
3. Which of the following cannot cause a drum on an air - braked vehicle to overheat ?
A. an over - tightened brake adjuster at that wheel
B. under - adjusted brake ( s ) elsewhere on the vehicle
C. too - high governor cut - out pressure
D. driving downhill in too high a gear. - ANS 3. The correct answer is C. The governor controls
the air compressor output by unloading or cycling it . It has no direct effect on the mechanical
brake parts . While the pressure setting is important to maintain air brake system pressure
within acceptable limits , an incorrect setting will not cause the drum on an air - braked vehicle
to overheat . All other choices given , however , will cause overheating problems .
4. All the brakes drag on a truck with hydraulic brakes . Which of the following could be the
cause ? A. air in the hydraulic system
B. too high a vacuum supply to the power brake booster
1 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
,C. a leaking secondary cup in the master cylinder
D. no brake pedal free travel - ANS 4. The correct answer is D. Only a brake pedal with no free
travel will cause all of the brakes to drag . Answer A - air in the hydraulic system , will cause a
spongy pedal , while answer B - too high a vacuum to the power booster , won't affect brake
drag at all . Answer C , a leaking secondary cup in the master cylinder , could increase pedal
travel , but won't cause the brakes to drag .
5. Which of the following could cause a pulsating brake pedal on a truck with hydraulic brakes ?
A. zero brake pedal free travel
B. glazed linings
C. an out - of - round brake drum
D. a frozen wheel cylinder piston. - ANS 5. The correct answer is C. Of the choices given , only
an out - of - round brake drum can cause pulsation in a hydrau lic brake system . Answer A , zero
brake pedal free travel , will cause a dragging brake condition , but not pulsation . Answer B ,
glazed linings , will affect stopping performance and noise , and answer D , a frozen wheel
cylinder , will de grade stopping performance , but will not cause pulsation.
6. Air pressure gauges change an air pressure signal into an electronic voltage signal using which
of the following components ?
A. inductor
B. capacitor
C. transducer
D. regulator - ANS 6. The correct answer is C. An element inside an air pressure transducer
responds to air pressure increase or decrease, and the transducer converts that pressure
differentiation into a voltage signal, which is displayed in a proportionate reading on the dash
gauge.
7. Technician A says that linings worn too thin on an air - braked vehicle can cause the S -
camshaft to roll over . Technician B says this condition can cause excess brake pedal travel . Who
is right ?
A. Technician A only
B. Technician B only
C. Both A and B
2 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
, D. Neither A or B - ANS 7. The correct answer is A. The brake adjuster is connected to a shaft
that runs perpendicular to the plane formed by the pushrod and slack adjuster. As the pushrod
is extended, the shaft rotates. The shaft, in turn, is connected to an S-shaped cam between the
brake shoes. As the shaft rotates, so does the cam. The brake shoes are forced apart and against
the brake drum, creating the friction needed to slow the vehicle. Thin brake linings can allow
the S-cam to roll over, but will not affect brake pedal travel.
8. Spring brakes on an air - braked vehicle must be able to hold the vehicle facing uphill or
downhill on what percent grade ?
A. 10 %
B. 20 %
C. 30 %
D. 40 % - ANS 8. The correct answer is B. Per Federal Motor Vehicle Safety Standard (FMVSS)
121, the parking brakes must be able to hold a vehicle, loaded to its gross weight rating,
stationary on a smooth, dry, concrete roadway, facing uphill or downhill on a 20% grade. In the
emergency mode, the parking brakes must be able to exert a retarding force equal to 28% of the
gross axle rating.
9. The driver of a truck with hydraulic brakes says the pedal reserve is too low . Technician A
says the brakes could be out of adjustment Technician B says one brake system may have failed .
Who is right ?
A. Technician A only
B. Technician B only
C. Both A and B
D. Neither A or B - ANS 9. The correct answer is C, both Technicians are right.
Either condition will cause the driver to notice a low pedal reserve.
10. The parking brakes fail to apply on a truck with air brakes . Technician A says this could be
caused by low air pressure in the spring brake chamber . Techni cian B says this could be caused
by a ruptured spring brake diaphragm . Who is right ?
A. Technician A only
B. Technician B only
C. Both A and B
3 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
