ASE A5 Brakes Practice Test
16. After replacing the front brake calipers on a vehicle with a four-wheel disc brake system, the vehicle returns with brake drag. Which of the following is causing this condition?
- A. Glazed brake shoes.
- B. Brake shoe adjustment.
- C. Glazed brake pads.
- D. A twisted brake hose.
Answer A is wrong. The vehicle has a four-wheel disc brake system; brake shoes found on drum brakes. Glazed brake shoes result from the excessive heat that's caused by a dragging brake unit. Glazing is more a problem with the shoes because brake pads are better ventilated.
Answer B is wrong. The vehicle has a four-wheel disc brake system; adjust the brake shoes on drum brake systems.
Answer C is wrong. Glazed brake pads result from the excessive heat that's caused by a dragging brake unit. Glazed shoes or pads cause brake fade resulting in a loss of friction and reduced braking performance.
Answer D is correct. A kinked brake line or twisted brake hose results in brake drag. Never let a brake caliper hang on the flexible brake hose and be careful not to twist the hose when reinstalling the caliper.
17. A pulsation is felt in the steering wheel of a four-wheel disc brake vehicle while braking. A lateral runout test is performed on all four rotors. Which of the following is correct about this test?
- A. This test checks for rotor thickness.
- B. This test checks for rotor parallelism.
- C. Use a dial indicator.
- D. Use an outside micrometer.
Answer A is wrong. Measure a rotor for parallelism or different thicknesses around the rotor's surface with an outside micrometer.
Answer B is wrong. Use an outside micrometer to measure the thickness of the rotor and compare it to the minimum thickness stamped on the rotor. This test is checking the rotor for parallelism. Check four to eight different spots around the rotor to find the thinnest spot.
Answer C is correct. Use a dial indicator to check a rotor for lateral runout (warpage). Runout can be caused by unevenly and excessively torqued lug nuts or studs, or a burr or rust between the hub and rotor.
Answer D is wrong. Parallelism is diagnosed by measuring several spots on the surface of the rotor with an outside micrometer.
A metric micrometer is used to measure a solid rotor for thickness. The reading above indicates:
- A. 13.0 mm
- B. 13.5 mm
- C. 14.0 mm
- D. 14.5 mm
Answer A is wrong. The answer is 14.5 mm. Metric micrometers are similar to standard micrometers.
Answer B is wrong. Whole number increments are on one side of the sleeve, and half-millimeter increments are on the other.
Answer C is wrong. The thimble of the micrometer has 50 increments of .01 millimeters.
Answer D is correct. The answer is 14.5 mm. It is important to remember that there are increments on both sides of the sleeve.
19. Which brake line is best suited for automotive brake line replacement?
- A. Double-walled steel tubing.
- B. Double-walled tin tubing.
- C. Single-walled seamless copper.
- D. Single-walled welded copper.
Answer A is correct. Automakers typically use double-walled steel tubing as their standard OEM brake line.
Answer B is wrong. Brake lines are replaced with OEM, aftermarket galvanized steel or fabricated lines made with metal tubing and fittings.
Answer C is wrong. They use double-walled steel tubing with either ISO or double-flared ends.
Answer D is wrong. In addition, some fabricators use more flexible nickel-copper alloy, never 100% copper tubing found in hardware stores.
20. Technician A says a three-function combination valve contains the proportioning valve. Technician B says a three-function combination valve contains the metering valve. Who is correct?
- A. Technician A
- B. Technician B
- C. Both A and B
- D. Neither A or B
Answer A is wrong. The proportioning valve is part of the combination valve.
Answer B is wrong. The metering valve is part of the combination valve.
Answer C is correct. Both technicians are correct.
Answer D is wrong. The brake failure light switch is also part of the combination valve.