T4 Brakes ASE Test Questions – Quiz & Review | Latest
Update 2026 | Exam Prep | Graded A+
1. Technician A is working on a vehicle that was brought in with excessive brake pedal
travel. The technician believes there is most likely an issue with the hydraulic system.
Technician B believes there is an issue with the lateral runout of the rotor. Which
technician is most likely correct?
Technician A
Neither Technician
Technician B
Both Technicians
2. When draining the air tanks, the technician should:
Open the drain valve for a maximum of two seconds.
Replace the single-check valves.
Start at the tank farthest from the compressor.
Start at the tank closest to the compressor.
3. What is the term used to describe the uneven surface of a brake rotor that can cause
chassis vibration during braking?
Worn brake pads
Air in the brake lines
Excessive rotor run out
Brake fluid contamination
,4. Before a vehicle with dual air brakes is driven, pressure of at least ____ should be
built up in both braking systems.
10 psi
50 psi
25 psi
100 psi
5. What could cause a truck to pull left after the brake pedal is released?
Low brake fluid levels
Faulty brake master cylinder
Worn brake pads on the right side
A restricted left-front brake hose
6. What can cause the rotor to knock the pads back and forth and result in a pulsating
pedal during braking?
Minimum allowable thickness.
Minimum brake pedal end play.
Excessive out-of-round.
Excessive lateral runout.
7. What is the recommended psi range for the air governor cut-out during testing?
25-30 psi
10-15 psi
20-25 psi
, 15-20 psi
8. The front brakes on a truck equipped with four-wheel hydraulic disc brakes pull when
stopping. All of the following could cause this EXCEPT:
A swollen flexible hose
A frozen caliper piston
A restricted flexible hose
A misadjusted parking brake
9. A slack adjuster is being adjusted. Technician A says wear between the clevis pin and
yoke will cause the stroke to be too long. Technician B says that an automatic slack
adjuster needs adjusting once a year. Who is correct?
Neither A nor B
Both A and B
B only
A only
10. What is the primary consequence of a broken air compressor unloader valve spring
in a truck brake system?
Slow air buildup time
Rapid air release
Increased brake pressure
Complete brake failure
11. If a truck experiences frequent brake fade, which drum failure condition should be
investigated first?
, Brinelling
Overheating
Misalignment
Cracking
12. What is one potential cause for an automatic slack adjuster failing to keep the brake
in adjustment according to Tech A?
Worn brake pads
Mismatched brake chambers
Low brake fluid
Incorrectly installed slack adjuster
13. What is the most likely cause of brake fluid leaking from the rear of the master
cylinder in a hydro boost brake system?
A brake line is damaged
The brake fluid reservoir is overfilled
A primary seal would be leaking
The hydro boost unit is malfunctioning
14. If a technician uses water instead of alcohol to clean ABS electric connectors, what
potential issue could arise?
Improved conductivity of the connectors
Enhanced insulation of the connectors
Corrosion or short-circuiting of the connectors
No effect on the performance of the connectors
Update 2026 | Exam Prep | Graded A+
1. Technician A is working on a vehicle that was brought in with excessive brake pedal
travel. The technician believes there is most likely an issue with the hydraulic system.
Technician B believes there is an issue with the lateral runout of the rotor. Which
technician is most likely correct?
Technician A
Neither Technician
Technician B
Both Technicians
2. When draining the air tanks, the technician should:
Open the drain valve for a maximum of two seconds.
Replace the single-check valves.
Start at the tank farthest from the compressor.
Start at the tank closest to the compressor.
3. What is the term used to describe the uneven surface of a brake rotor that can cause
chassis vibration during braking?
Worn brake pads
Air in the brake lines
Excessive rotor run out
Brake fluid contamination
,4. Before a vehicle with dual air brakes is driven, pressure of at least ____ should be
built up in both braking systems.
10 psi
50 psi
25 psi
100 psi
5. What could cause a truck to pull left after the brake pedal is released?
Low brake fluid levels
Faulty brake master cylinder
Worn brake pads on the right side
A restricted left-front brake hose
6. What can cause the rotor to knock the pads back and forth and result in a pulsating
pedal during braking?
Minimum allowable thickness.
Minimum brake pedal end play.
Excessive out-of-round.
Excessive lateral runout.
7. What is the recommended psi range for the air governor cut-out during testing?
25-30 psi
10-15 psi
20-25 psi
, 15-20 psi
8. The front brakes on a truck equipped with four-wheel hydraulic disc brakes pull when
stopping. All of the following could cause this EXCEPT:
A swollen flexible hose
A frozen caliper piston
A restricted flexible hose
A misadjusted parking brake
9. A slack adjuster is being adjusted. Technician A says wear between the clevis pin and
yoke will cause the stroke to be too long. Technician B says that an automatic slack
adjuster needs adjusting once a year. Who is correct?
Neither A nor B
Both A and B
B only
A only
10. What is the primary consequence of a broken air compressor unloader valve spring
in a truck brake system?
Slow air buildup time
Rapid air release
Increased brake pressure
Complete brake failure
11. If a truck experiences frequent brake fade, which drum failure condition should be
investigated first?
, Brinelling
Overheating
Misalignment
Cracking
12. What is one potential cause for an automatic slack adjuster failing to keep the brake
in adjustment according to Tech A?
Worn brake pads
Mismatched brake chambers
Low brake fluid
Incorrectly installed slack adjuster
13. What is the most likely cause of brake fluid leaking from the rear of the master
cylinder in a hydro boost brake system?
A brake line is damaged
The brake fluid reservoir is overfilled
A primary seal would be leaking
The hydro boost unit is malfunctioning
14. If a technician uses water instead of alcohol to clean ABS electric connectors, what
potential issue could arise?
Improved conductivity of the connectors
Enhanced insulation of the connectors
Corrosion or short-circuiting of the connectors
No effect on the performance of the connectors
