ASE A5 Brakes Questions and Answers
A hydro-boost brake system has reduced braking performance. Technician A says to check the power
steering system. Technician B says to check the vacuum check valve. Who is correct?
TECH A is correct. The power steering pump produces pressure for the Hydro-Boost unit.
A vehicle with power assisted brakes has a hard brake pedal. Which of the following is LEAST likely to
cause this condition?
A. Master cylinder.
B. Vacuum check valve.
C. Brake booster.
D. Low manifold vacuum.
Answer A is correct. Faulty master cylinders do not typically result in a hard brake pedal. Actually it's
more common for a faulty master cylinder to cause a low brake pedal that fades to the floor as it is
applied. This is the least likely component listed to result in a hard brake pedal.
A vehicle pulls to the left only when the brakes are applied. This condition is MOST likely caused by:
A. A seized left front caliper.
B. A restriction in the left front brake line.
C. Leaking master cylinder cup seals.
D. A seized right front caliper.
Answer D is correct. A frozen right front caliper will cause the vehicle to pull to the left when braking.
Technician A says accumulators are found only on non-integral ABS systems. Technician B says some
integral ABS units contain high pressure accumulators that must be discharged before repair. Who is
correct?
TECH B is correct. High pressure units can be dangerous and must be discharged before removal. Always
check with manufacturer's procedures before disassembling an ABS unit
Technician A says ABS control units are programmed to ignore speed sensor input variations below a
certain threshold. Technician B says a one-channel ABS system controls hydraulic pressure to the rear
brake units. Who is correct?
Both technicians are correct.
A vehicle's right front wheel has a growl that increases with vehicle speed. The MOST likely cause is:
A. Excessive rotor lateral run out.
B. Warped rear brake drums.
, C. Worn CV-Joint.
D. Worn wheel bearing.
Answer D is correct. A worn wheel bearing will cause a growl that increases with vehicle speed.
Two technicians are discussing master cylinder residual check valves. Technician A says the check
valve is used on four wheel disc brake systems. Technician B says the valve maintains pressure when
the brakes are released. Who is correct?
Technician B is correct. The constant low pressure, usually 6 psi to 8 psi keeps air from entering the
wheel cylinders.
The brake pad wear indicator light is illuminated on the instrument panel. Technician A says this is
because the brake pads have become contaminated. Technician B says this is the pad wear sensor
contacting the brake rotor. Who is correct?
TECH B is correct. When the sensors tip contacts the rotor, the pad warning light illuminates on the
instrument panel.
A vehicle with ABS anti-lock brakes has an audible clicking noise when it is first started. The noise goes
away after a few seconds. Technician A says this is one of the hydraulic valves in the hydraulic valve
assembly sticking. Technician B says this is a normal condition. Who is correct?
TECH B is correct. The ABS system runs a system check when the key is first turned to the ON position.
The valves sometimes make a clicking noise during this check.
The rear wheels of a vehicle are locking up only when the brakes are applied. This is caused by a
faulty:
A. Metering valve.
B. Pressure differential switch.
C. Proportioning valve.
D. Brake switch.
Answer C is correct. The proportioning valve prevents rear wheel lockup.
Which of the following brake fluids are silicone based.
A. Dot 2
B. Dot 3
C. Dot 4
D. Dot 5
Answer D is correct. Dot 5 brake fluid is silicon based.
A vehicle stops but the brake pedal fades completely to the floorboard afterwards. There are no
external leaks. Which of these is the MOST likely cause of this condition.
A. Faulty vacuum brake booster.
B. Clogged vacuum booster check valve.
C. Dark discolored brake fluid.
D. Master cylinder cup seals.
A hydro-boost brake system has reduced braking performance. Technician A says to check the power
steering system. Technician B says to check the vacuum check valve. Who is correct?
TECH A is correct. The power steering pump produces pressure for the Hydro-Boost unit.
A vehicle with power assisted brakes has a hard brake pedal. Which of the following is LEAST likely to
cause this condition?
A. Master cylinder.
B. Vacuum check valve.
C. Brake booster.
D. Low manifold vacuum.
Answer A is correct. Faulty master cylinders do not typically result in a hard brake pedal. Actually it's
more common for a faulty master cylinder to cause a low brake pedal that fades to the floor as it is
applied. This is the least likely component listed to result in a hard brake pedal.
A vehicle pulls to the left only when the brakes are applied. This condition is MOST likely caused by:
A. A seized left front caliper.
B. A restriction in the left front brake line.
C. Leaking master cylinder cup seals.
D. A seized right front caliper.
Answer D is correct. A frozen right front caliper will cause the vehicle to pull to the left when braking.
Technician A says accumulators are found only on non-integral ABS systems. Technician B says some
integral ABS units contain high pressure accumulators that must be discharged before repair. Who is
correct?
TECH B is correct. High pressure units can be dangerous and must be discharged before removal. Always
check with manufacturer's procedures before disassembling an ABS unit
Technician A says ABS control units are programmed to ignore speed sensor input variations below a
certain threshold. Technician B says a one-channel ABS system controls hydraulic pressure to the rear
brake units. Who is correct?
Both technicians are correct.
A vehicle's right front wheel has a growl that increases with vehicle speed. The MOST likely cause is:
A. Excessive rotor lateral run out.
B. Warped rear brake drums.
, C. Worn CV-Joint.
D. Worn wheel bearing.
Answer D is correct. A worn wheel bearing will cause a growl that increases with vehicle speed.
Two technicians are discussing master cylinder residual check valves. Technician A says the check
valve is used on four wheel disc brake systems. Technician B says the valve maintains pressure when
the brakes are released. Who is correct?
Technician B is correct. The constant low pressure, usually 6 psi to 8 psi keeps air from entering the
wheel cylinders.
The brake pad wear indicator light is illuminated on the instrument panel. Technician A says this is
because the brake pads have become contaminated. Technician B says this is the pad wear sensor
contacting the brake rotor. Who is correct?
TECH B is correct. When the sensors tip contacts the rotor, the pad warning light illuminates on the
instrument panel.
A vehicle with ABS anti-lock brakes has an audible clicking noise when it is first started. The noise goes
away after a few seconds. Technician A says this is one of the hydraulic valves in the hydraulic valve
assembly sticking. Technician B says this is a normal condition. Who is correct?
TECH B is correct. The ABS system runs a system check when the key is first turned to the ON position.
The valves sometimes make a clicking noise during this check.
The rear wheels of a vehicle are locking up only when the brakes are applied. This is caused by a
faulty:
A. Metering valve.
B. Pressure differential switch.
C. Proportioning valve.
D. Brake switch.
Answer C is correct. The proportioning valve prevents rear wheel lockup.
Which of the following brake fluids are silicone based.
A. Dot 2
B. Dot 3
C. Dot 4
D. Dot 5
Answer D is correct. Dot 5 brake fluid is silicon based.
A vehicle stops but the brake pedal fades completely to the floorboard afterwards. There are no
external leaks. Which of these is the MOST likely cause of this condition.
A. Faulty vacuum brake booster.
B. Clogged vacuum booster check valve.
C. Dark discolored brake fluid.
D. Master cylinder cup seals.
