ASE A5 Brakes Practice Test
6. After a test drive, one brake rotor is much hotter than the others. Which of the following is MOST likely causing this condition?
- A. A frozen brake caliper.
- B. Frozen slide pins.
- C. A sticking caliper piston seal.
- D. Aerated brake fluid.
Answer A is wrong. A frozen brake caliper causes the vehicle to pull to the side with the functioning caliper.
Answer B is wrong. Frozen slide pins cause uneven pad wear with floating caliper brake systems. If the slide pins are frozen, the outboard pad doesn't slide into contact with the side of the rotor. The inside pad does most, if not all, of the braking.
Answer C is correct. If the seal does not retract the piston, the brake drags as the pad stays in contact with the rotor. Overhaul kits contain a new boot and seal. Square-cut piston seals and other rubber components are sensitive to water, oil, and brake fluid contamination.
Answer D is wrong. Friction causes the rotor to overheat, deform, and warp. It can cause the vehicle to pull to the side that's dragging.
7. The control module has illuminated the ESP warning lamp on a vehicle with ESP traction control, and the car drifts to the right during the test drive. The car has had a four-wheel alignment, and the hydraulic brake system and pads are in good condition and not dragging. Which of the following is MOST likely causing this condition?
- A. The lateral acceleration sensor.
- B. The steering angle sensor.
- C. A wheel speed sensor.
- D. The yaw rate sensor.
Answer A is wrong. The lateral acceleration sensor is also known as the G-sensor. It can sense the momentum and force pushing a car sideways in a sharp turn, G-force.
Answer B is correct. The steering angle sensor, Code U0126, can cause issues like drift or pull, and sometimes needs recalibration after a wheel alignment. They are often combined with the clock spring.
Answer C is wrong. The four-wheel speed sensors report the rotational wheel speed of each wheel.
Answer D is wrong. The steering angle sensor informs the ABS/ESP module of the driver's intentions, and the yaw rate, lateral acceleration, and wheel speed sensors report the vehicle's actual speed and direction.
8. One of the brake shoes on the rear drum brakes has worn more than the other. Which of the following is causing this condition?
- A. Overadjusted brake shoes.
- B. A sticking wheel cylinder.
- C. Weak brake springs.
- D. A leaking wheel cylinder.
Answer A is wrong. Overadjusting the brake shoes results in premature wear and can cause brake lockup with only light pedal pressure.
Answer B is correct. Wheel cylinders contain pistons that can stick, affecting brake shoe application. It may be hard to notice without inspection because the other shoe contacts the drum and slows the vehicle.
Answer C is wrong. Heat and fatigue can wear brake springs; it results in brake binding and drag.
Answer D is wrong. Leaking internal cup seals are the most common problem encountered with wheel cylinders.
9. A vehicle with a four-wheel disc ABS brake system has a slight clicking sound when it's first started in the morning. The noise goes away after a few seconds. Which of the following is MOST likely making this noise?
- A. The brake switch.
- B. The ABS modulator assembly.
- C. The brake pads are shifting.
- D. The vacuum brake booster.
Answer A is wrong. A faulty brake switch typically results in brake light failure. The ABS pump/modular assembly contains a pump and valves that sometimes click when activated. An audible click is normal when a vehicle is first started or has been sitting for a while.
Answer B is correct. The ABS system runs a system check when the key is first turned to the ON position. The valves can make a clicking noise during this check.
Answer C is wrong. Loose brake pads can make a clunking sound when the brake is applied.
Answer D is wrong. Brake boosters hiss but do not make a clicking noise. The ABS brake system runs a system check when the vehicle is first started. The system lies dormant during normal operation, and the standard brake system is used.
10. The rear drum brakes of a light truck are locking up with only light pressure applied to the brake pedal. Which of the following is causing this condition?
- A. A faulty proportioning valve.
- B. The pressure differential switch.
- C. A faulty metering valve.
- D. A faulty brake switch.
Answer A is correct. A faulty proportioning valve locks the rear brakes up with only light to moderate pressure applied to the brake pedal. They lock up as the vehicle's weight shifts toward the front wheels.
Answer B is wrong. The pressure differential switch warns the driver of a hydraulic leak.
Answer C is wrong. A brake metering valve, similar to the proportioning valve, is also used to achieve balanced braking. Front-disc rear-drum brake systems use the valves. The metering valve delays fluid pressure to the front calipers long enough to overcome the rear brake springs and linkage. This delay achieves even brake application of the front and rear brakes.
Answer D is wrong. The brake switch is part of the brake light system.