T4 BRAKES ASE EXAM SCRIPT 2026
COMPREHENSIVE QUESTIONS WITH
SOLUTIONS GRADED A+
⩥ 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. Answer: daily
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 deficienc
⩥ Which of the following could cause a pulsating brake pedal on a truck
with hydraulic brakes?
A. zero brake pedal free travel
B. glazed liningsIncorrect
C. an out-of-round brake drumCorrect answer
D. a frozen wheel cylinder piston. Answer: C. too-high governor cut-out
pressure
,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
⩥ All the brakes drag on a truck with hydraulic brakes. Which of the
following could be the cause?
A. air in the hydraulic systemIncorrect
B. too high a vacuum supply to the power brake booster
C. a leaking secondary cup in the master cylinder
D. no brake pedal free travel. Answer: D. no brake pedal free travel
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.
⩥ Which of the following could cause a pulsating brake pedal on a truck
with hydraulic brakes?
A. zero brake pedal free travel
B. glazed liningsIncorrect
C. an out-of-round brake drum
,D. a frozen wheel cylinder piston. Answer: C. an out-of-round brake
drum
The correct answer is C. Of the choices given, only an out-of-round
brake drum can cause pulsation in a hydraulic 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
degrade stopping performance, but will not cause pulsation.
⩥ 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. Answer: 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.
⩥ 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
, D. Neither A or B. Answer: 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 rollover but will not
affect brake pedal travel.
⩥ 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%. Answer: 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.
⩥ 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. Technician B says this could be caused by a ruptured spring
brake diaphragm. Who is right?
A. Technician A only
COMPREHENSIVE QUESTIONS WITH
SOLUTIONS GRADED A+
⩥ 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. Answer: daily
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 deficienc
⩥ Which of the following could cause a pulsating brake pedal on a truck
with hydraulic brakes?
A. zero brake pedal free travel
B. glazed liningsIncorrect
C. an out-of-round brake drumCorrect answer
D. a frozen wheel cylinder piston. Answer: C. too-high governor cut-out
pressure
,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
⩥ All the brakes drag on a truck with hydraulic brakes. Which of the
following could be the cause?
A. air in the hydraulic systemIncorrect
B. too high a vacuum supply to the power brake booster
C. a leaking secondary cup in the master cylinder
D. no brake pedal free travel. Answer: D. no brake pedal free travel
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.
⩥ Which of the following could cause a pulsating brake pedal on a truck
with hydraulic brakes?
A. zero brake pedal free travel
B. glazed liningsIncorrect
C. an out-of-round brake drum
,D. a frozen wheel cylinder piston. Answer: C. an out-of-round brake
drum
The correct answer is C. Of the choices given, only an out-of-round
brake drum can cause pulsation in a hydraulic 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
degrade stopping performance, but will not cause pulsation.
⩥ 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. Answer: 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.
⩥ 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
, D. Neither A or B. Answer: 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 rollover but will not
affect brake pedal travel.
⩥ 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%. Answer: 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.
⩥ 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. Technician B says this could be caused by a ruptured spring
brake diaphragm. Who is right?
A. Technician A only
