ASE A5 Brakes Practice Test

26. A ridge has formed on the backing plate's pads where the brake shoes rest. All of the following are correct EXCEPT:

  • A. Apply bearing grease to reduce brake squeak.
  • B. They may be filed to restore a smooth finish.
  • C. They may be sanded to restore a smooth finish.
  • D. Apply a lubricant for high-temperature brake systems.

26.

Answer A is correct. Avoid petroleum-based greases that can swell rubber parts and chassis greases that burn off and evaporate.

Answer B is wrong. The shoe pads on the backing plate can become scuffed and grooved as the shoes move back and forth on its surface. These pads can be sanded or filed smooth to restore surface integrity.

Answer C is wrong. Steel plate backing plates are used to hold and assemble wheel cylinders, brake shoes, and other related hardware onto a drum brake unit.

Answer D is wrong. Always use the proper high-temperature lubricant between the backing plate and the shoe.

27. A four-wheel disc brake system with a vacuum brake booster has a low spongy brake pedal. Which of the following is causing this condition?

  • A. A faulty vacuum check valve.
  • B. A faulty brake booster.
  • C. Overheated brake fluid.
  • D. Low power steering fluid.

27.

Answer A is wrong. Vacuum boosters use a vacuum check valve that allows air to flow in only one direction. This valve maintains a vacuum in the booster at wide-open throttle or when the engine is shut down.

Answer B is wrong. Check if the vehicle has a hard brake pedal and is having difficulty stopping; if so, suspect the brake booster or vacuum check valve.

Answer C is correct. Heat and time degrade brake fluid. Excessive heat from the braking system can cause the fluid to boil and vaporize, leaving pockets of vapor in the brake lines. This vapor is compressible and results in a low spongy pedal.

Answer D is wrong. Hydroboost brake systems use pressure from the power steering system instead of vacuum as a source of power assist.

28. A vehicle with a four-wheel disc ABS brake system is difficult to bleed and still has a low spongy brake pedal. Technician A says the master cylinder may have faulty cup seals. Technician B says to bleed the ABS hydraulic modulator valve assembly. Who is correct?

  • A. Technician A
  • B. Technician B
  • C. Both A and B
  • D. Neither A or B

28.

Answer A is wrong. Isolate the master cylinder by blocking the outlet ports with plugs and checking the pedal for firmness. If the pedal is firm, the master cylinder cup seals are good, and the problem exists downstream.

Answer B is wrong. There may be air trapped in the ABS unit, a line or hose, or in one of the brake units. If the master cylinder and brake units have no air pockets and the pedal is still low, there may be air trapped in the hydraulic ABS unit.

Answer C is correct. Air trapped in the brake system results in a spongy brake pedal because air is compressible.

Answer D is wrong. Both Technicians are correct.

29. A height sensing proportioning valve:

  • A. Delays pressure to the front brakes.
  • B. Prevents rear wheel lock-up.
  • C. Prevents nosedive while braking.
  • D. Is adjusted with all four tires raised in the air.

29.

Answer A is wrong. The metering valve holds off pressure to the front brakes until the rear drum brakes overcome spring pressure.

Answer B is correct. Proportioning valves enable balanced braking by reducing hydraulic pressure to the rear brake units during sudden and panicked braking. This reduction in pressure helps prevent rear-wheel lockup.

Answer C is wrong. The metering valve prevents nosedive.

Answer D is wrong. Adjust a height sensing proportioning valve at curb height with all four tires firm on the ground. Adjusting this type of proportioning valve on a lift would reduce rear brake performance.

30. The amber ABS warning light on a light truck with four-wheel ABS is illuminated. A scan indicates a problem with the left rear wheel speed sensor. Technician A says mud and road debris can get in the gap or between the tone sprockets damaging the sensor and creating a problem with the signal. Technician B says to check the wheel bearing for looseness and wear. Who is correct?

  • A. Technician A
  • B. Technician B
  • C. Both A and B
  • D. Neither A or B

30.

Answer A is wrong. Mud and road debris can get in the gap or between the tone sprockets creating a problem with the signal.

Answer B is wrong. The tone rings for these speed sensors spin with the hub or CV axle; loose wheel bearings cause the sensor's ring to wobble.

Answer C is correct. Both technicians are correct.

Answer D is wrong. Inspect the wheel bearings by grasping the tire at the top and bottom and rocking it back and forth. Excessive play indicates a loose wheel bearing.