©GRACEAMELIA 2024/2025 ACADEMIC YEAR. ALL RIGHTS RESERVED
FIRST PUBLISH OCTOBER 2024
Diesel Tech Brakes ASE Practice Test 2
Practice Questions and Answers
Technician A says the same electronic control unit (ECU) operates the antilock braking systems (ABS) on
the tractor and the trailer. Technician B says that if replacement tires are a different size from the original
tires, the wheel speed sensor signals are affected. Who is correct?
A. A only
B. B only
C. Both A and B
D. Neither A nor B - Ans:✔✔-B. B only
A truck with air brakes and a suspended (fire-mounted) pedal has a low pedal. Which of the following
could be the cause?
A. The brakes are adjusted too tight
B. No air pressure in the primary brake circuit
C. The brake pedal pushrod is too long
Page 1/19
, ©GRACEAMELIA 2024/2025 ACADEMIC YEAR. ALL RIGHTS RESERVED
FIRST PUBLISH OCTOBER 2024
D. The parking brake is broken - Ans:✔✔-B. No air pressure in the primary brake circuit
A truck with hydraulic disc brakes has dragging brakes. Technician A says the calipers may be sticking.
Technician B says the master cylinder may be passing fluid. Who id correct?
A. A only
B. B only
C. Both A and B
D. Neither A nor B - Ans:✔✔-A. A only
Which of the following could cause one brake on a truck to wear faster than the others?
A. A restricted service brake hose
B. A restricted air line between the supply and primary tank
C. Low air pressure in the service tanks
D. Governor cut-out pressure too high - Ans:✔✔-A. A restricted service brake hose
The front brakes on a truck are being checked. The drum rolls freely backward, but hangs and stops
when rotated forward by hand. Technician A says the problem could be a broken slack adjuster.
Technician B says the problem could be an incorrectly adjusted hand brake valve. Who is correct?
Page 2/19
, ©GRACEAMELIA 2024/2025 ACADEMIC YEAR. ALL RIGHTS RESERVED
FIRST PUBLISH OCTOBER 2024
A. A only
B. B only
C. Both A and B
D. Neither A nor B - Ans:✔✔-D. Neither A nor B
On a tractor-trailer combination with air brakes, the parking brake on the tractor will not release, but the
trailer brakes work correctly. Which of the following is the most likely cause?
A. Shorted brake light switch
B. Stuck parking brake relay valve
C. Stuck service brake relay valve
D. A hand valve slightly stuck on - Ans:✔✔-B. Stuck parking brake relay valve
A technician is testing a hydraulic brake booster. With the engine off, the brake pedal depresses 1.5
inches, then the engine is started and the brake pedal falls another inch. Technician A says this indicates
a faulty master cylinder. Technician B says this indicates a faulty brake booster. Who is correct?
A. A only
B. B only
Page 3/19
FIRST PUBLISH OCTOBER 2024
Diesel Tech Brakes ASE Practice Test 2
Practice Questions and Answers
Technician A says the same electronic control unit (ECU) operates the antilock braking systems (ABS) on
the tractor and the trailer. Technician B says that if replacement tires are a different size from the original
tires, the wheel speed sensor signals are affected. Who is correct?
A. A only
B. B only
C. Both A and B
D. Neither A nor B - Ans:✔✔-B. B only
A truck with air brakes and a suspended (fire-mounted) pedal has a low pedal. Which of the following
could be the cause?
A. The brakes are adjusted too tight
B. No air pressure in the primary brake circuit
C. The brake pedal pushrod is too long
Page 1/19
, ©GRACEAMELIA 2024/2025 ACADEMIC YEAR. ALL RIGHTS RESERVED
FIRST PUBLISH OCTOBER 2024
D. The parking brake is broken - Ans:✔✔-B. No air pressure in the primary brake circuit
A truck with hydraulic disc brakes has dragging brakes. Technician A says the calipers may be sticking.
Technician B says the master cylinder may be passing fluid. Who id correct?
A. A only
B. B only
C. Both A and B
D. Neither A nor B - Ans:✔✔-A. A only
Which of the following could cause one brake on a truck to wear faster than the others?
A. A restricted service brake hose
B. A restricted air line between the supply and primary tank
C. Low air pressure in the service tanks
D. Governor cut-out pressure too high - Ans:✔✔-A. A restricted service brake hose
The front brakes on a truck are being checked. The drum rolls freely backward, but hangs and stops
when rotated forward by hand. Technician A says the problem could be a broken slack adjuster.
Technician B says the problem could be an incorrectly adjusted hand brake valve. Who is correct?
Page 2/19
, ©GRACEAMELIA 2024/2025 ACADEMIC YEAR. ALL RIGHTS RESERVED
FIRST PUBLISH OCTOBER 2024
A. A only
B. B only
C. Both A and B
D. Neither A nor B - Ans:✔✔-D. Neither A nor B
On a tractor-trailer combination with air brakes, the parking brake on the tractor will not release, but the
trailer brakes work correctly. Which of the following is the most likely cause?
A. Shorted brake light switch
B. Stuck parking brake relay valve
C. Stuck service brake relay valve
D. A hand valve slightly stuck on - Ans:✔✔-B. Stuck parking brake relay valve
A technician is testing a hydraulic brake booster. With the engine off, the brake pedal depresses 1.5
inches, then the engine is started and the brake pedal falls another inch. Technician A says this indicates
a faulty master cylinder. Technician B says this indicates a faulty brake booster. Who is correct?
A. A only
B. B only
Page 3/19
