ASE A5 Brakes Practice Test
11. Which of the following brake fluids is silicon-based and found in special applications like show cars?
- A. Dot 5.1
- B. Dot 3
- C. Dot 4
- D. Dot 5
Answer A is wrong. DOT 5.1 is a different chemistry; it's a non-silicon based alternative that should not be mixed with DOT 5 brake fluid.
Answer B is wrong. Most of today's vehicles use DOT 3 or DOT 4, a glycol (Polyalkylene Glycol Ether) based brake fluid.
Answer C is wrong. Dot 5 is silicon-based, DOT 4 is a common glycol-based brake fluid.
Answer D is correct. Silicon-based fluid (DOT 5) is usually found in special applications like show cars because it doesn't damage painted surfaces like its glycol counterpart.
12. A vehicle's brake pedal fades to the floorboard resulting in vehicle creep at stoplights. An initial inspection indicates there are no external leaks found. Which of the following is MOST likely causing this brake pedal to fade?
- A. Contaminated brake fluid.
- B. Leaking master cylinder cup seals.
- C. Vacuum brake booster failure.
- D. A faulty metering valve.
Answer A is wrong. Old and contaminated brake fluid affects braking performance and results in a spongy brake pedal. A brake fluid flush will be necessary.
Answer B is correct. Master cylinder cup seals wear, as fluid bypasses the seal, the brake pedal fades to the floorboard.
Answer C is wrong. A faulty brake booster results in no or little brake assist resulting in a hard brake pedal.
Answer D is wrong. Front disc rear drum brake systems have metering valves to overcome rear drum spring pressure and achieve balanced braking.
13. Which of the following flaws requires replacement of a brake drum?
- A. Minor pitting.
- B. Slight scoring.
- C. Small cracks.
- D. Slightly out of round.
Answer A is wrong. When a drum shows signs of minor pitting, it may be machined.
Answer B is wrong. When a drum shows signs of minor scoring, it may be machined.
Answer C is correct. If a brake drum is beginning to crack, it cannot be machined and must be replaced. Small cracks lead to big ones, and the crack may be deeper in the cast than it appears.
Answer D is wrong. Measure the inside of the brake drum with a brake drum micrometer. Never turn a drum or rotor out of these specifications. They apply to the drum's inner surface after it turning the drum, not before.
14. 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?
- A. Technician A
- B. Technician B
- C. Both A and B
- D. Neither A or B
Answer A is wrong. Accumulators are found on integral and non-integral ABS systems.
Answer B is correct. High-pressure units can be dangerous and must be discharged before removal. Always check with the manufacturer's procedures before disassembling an ABS unit.
Answer C is wrong. Technician B is correct.
Answer D is wrong. Technician B is correct.
15. A technician is replacing a brake hose and a damaged section of brake line tubing. Which of the following is correct?
- A. Repair damaged brake line with a compression fitting.
- B. Use double-walled steel tubing.
- C. Use single-walled copper tubing.
- D. Re-use the original brass washer when replacing a brake hose.
Answer A is wrong. Compression fittings can not safely withstand the high pressure produced by automotive brake systems.
Answer B is correct. Brake lines are made from double-walled steel tubing and coated with tin or an alloy capable of resisting rust and corrosion.
Answer C is wrong. Do not use copper tubing on automotive brake systems because it is unable to withstand the high pressure and vibrations double-walled steel tubing can.
Answer D is wrong. Never re-use the same brass washer when replacing a worn brake hose. Always replace these washers with the new ones provided by the manufacturer.