ASE Brakes
19) A front-wheel drive vehicle has contaminated rear brake shoes.Technician A says that a leaking wheel cylinder could be the cause.Technician B says that an out-of-round brake drum could be the cause.Who is right?
A only Explanation: A leaking wheel cylinder can contaminate the rear shoes. Technician A's statement is true. An out-of-round brake drum may cause pulsation with the brakes applied, but will not cause contamination. Technician B's statement is false. The correct answer is A.
17) Technician A says that a loose front wheel bearing can affect ABS operation.Technician B says that worn brake pads can affect ABS operation.Who is right?
A only Explanation: A loose wheel bearing may affect wheel speed sensor operation. Technician A's statement is true. Worn brake pads will not affect the operation of the ABS. Technician B's statement is false. The correct answer is A.
22 The brake pedal in a vehicle equipped with anti-lock brakes goes to the floor.Technician A says that an external leak in the hydraulic actuator assembly could be the cause.Technician B says that an open in the ABS pump motor winding could be the cause.Who is right?
A only Explanation: The hydraulic actuator assembly is in series with the hydraulic brake system so a leak anywhere in the system will cause the brake pedal to go to the floor. Technician A's statement is true. An open in the ABS pump winding will prevent the ABS system from functioning but will not affect the base braking system. Technician B's statement is false. The correct answer is A.
2) A vehicle's brake pedal goes to the floor. Technician A says that an internal master cylinder leak could be the cause. Technician B says that seized wheel cylinder pistons could be the cause. Who is right?
A only Explanation: Fluid bypassing the master cylinder primary cup may cause the brake pedal to go to the floor. Technician A's statement is true. Seized wheel cylinder pistons will not cause the brake pedal to go to the floor. Technician B's statement is false. The correct answer is A.
5) Technician A says that the bleeder valve on the caliper should be opened when collapsing a caliper piston.Technician B says that the brake hose should be clamped when collapsing a caliper piston.Who is right?
A only Explanation: The purpose of opening the bleeder is to prevent contaminated fluid in the caliper from being pushed back into the hydraulic system. Technician A's statement is true. The brake hose should never be clamped as this may cause damage to the hose. Technician B's statement is false. The correct answer is A.
14) During a test drive, the technician finds that the brakes drag. During an inspection with the engine off, the technician observes that the wheels turn freely. Which of these could be the cause?
A plugged brake booster vent Explanation: No vacuum to the booster will only cause a hard pedal. A sticking master cylinder or brake pedal assembly will cause the brakes to drag with the engine ON or OFF. A plugged brake booster vent can keep the brake pedal applied, by not allowing the pressure to equalize. The correct answer is D.
16) A vehicle's parking brake remains engaged after the parking brake mechanism is released. Which of these could be the cause?
A seized equalizer bar Explanation: The transmission parking pawl will not affect the parking brake operation. A seized star adjuster may cause excessive clearance between the brake shoes and the drum. Water contaminated brake fluid will not cause the parking brake to remain applied. The equalizer bar on a rear drum brake assembly may seize in the extended position and create the symptom. The correct answer is C.
10) A vehicle has a pull to the right when braking. Which of these could be the cause?
A seized left front caliper Explanation: The vehicle will pull to the opposite side of the seized caliper. A leaking brake booster will cause a hard brake pedal. A warped brake rotor may cause a brake pulsation, but not a pull to one side. The correct answer is A.
7) A vehicle has a low brake pedal. Which of these could be the cause?
A seized star adjuster Explanation: A stuck-open metering valve will not cause a pedal drop, nor will a stuck-open proportioning valve or a seized caliper piston. A seized star adjuster will lead to excessive clearance between the brake shoes and the drum, requiring additional pedal travel. The correct answer is D.
20) The electronic stability control (ESC) system malfunction indicator lamp (MIL) is illuminated. Which of these could be the cause?
An open steering angle sensor circuit Explanation: Air in the brake hydraulic system or an over-filled master cylinder reservoir will not cause the ESC MIL to illuminate. A good electrical connection has low resistance. An open in the steering angle sensor circuit may cause the ESC MIL to illuminate. The correct answer is C.
13) The inboard pad of a single piston caliper is worn more than the outboard pad.Technician A says that a stuck-applied caliper piston could be the cause.Technician B says that seized caliper slides could be the cause.Who is right?
B only Explanation: A stuck-applied caliper piston will apply pressure evenly to both pads. Technician A's statement is false. A seized caliper slide may prevent the outboard pad from applying causing the inboard pad to wear more than the outboard pad. Technician B's statement is true. The correct answer is B.
18) A vehicle is being diagnosed for an illuminated red brake warning light.Technician A says that an open lamp control circuit could be the cause.Technician B says that an off center pressure differential switch could be the cause.Who is right?
B only Explanation: An open circuit that controls the red brake warning lamp will not allow the lamp to illuminate. Technician A's statement is false. An off-center differential switch will cause the red brake warning light to turn on. Technician B's statement is true. The correct answer is B.
1) The brake pedal feels soft after the master cylinder has been replaced. Technician A says that a leaking power booster could be the cause. Technician B says that air in the hydraulic system could be the cause. Who is right?
B only Explanation: A leaking power brake booster will cause the brake pedal to be hard. Technician A's statement is false. Air in the hydraulic system may cause the pedal to be soft. Technician B's statement is true. The correct answer is B.
6) Technician A says that DOT 5 brake fluid can be substituted where DOT 3 brake fluid is specified.Technician B says that a scan tool may be required to bleed the brakes on some vehicles.Who is right?
B only Explanation: DOT 5 brake fluid is not compatible with DOT 3 brake fluid. Technician A's statement is false. Some vehicles with ABS or TCS may require a scan tool to activate the system to properly bleed brakes. Technician B's statement is true. The correct answer is B.
9) A vehicle has pulsating brakes.Technician A says that a brake rotor with excessive lateral run-out could be the cause.Technician B says that corrosion on the hub flange could be the cause.Who is right?
Both A and B Explanation: Excessive lateral run out is a common cause of brake pulsation. This will be caused by a rotor with excessive lateral run-out or an uneven mounting surface. Both Technician A and B are making true statements. The correct answer is C.
15) A customer states that the vehicle takes too long to stop and the pedal is high. Which of these could be the cause?
Leaking brake booster vacuum hose Explanation: A leaking brake booster vacuum hose will cause lack of brake assist and a high pedal. A leaking hydraulic actuator assembly, a leaking master cylinder assembly, or a leaking proportioning valve will cause a low pedal. The correct answer is A.
21) The scan data graph shown was observed during diagnosis of a vehicle with a complaint of ABS activation during light braking on dry pavement. Which of these could be the cause?
Missing left front tone ring teeth Explanation: The pattern shown indicates that the left front wheel speed sensor signal drops to 0 MPH at regular intervals. Missing teeth on the left front tone ring will cause this condition. The correct answer is D.
11) Technician A says that wheel bearing grease should be used to lubricate backing plate contact points.Technician B says that wheel bearing grease should be used to lubricate brake caliper slides and pins.Who is right?
Neither A nor B Explanation: Wheel bearing grease is not an approved lubricant for brake contact points and slides. Both Technicians A and B are making false statements. The correct answer is D.
4) The front of the vehicle dips noticeably during braking on a vehicle with disc/drum brakes. Which of these could be the cause?
Stuck-open metering valve Explanation: The proportioning valve moderates pressure to the rear wheels. A collapsed front brake hose or seized caliper pistons will not cause the symptom. A stuck-open metering valve will allow the front brakes to apply too soon causing the front of the vehicle to dip. The correct answer is B.
8) The primary shoe of the rear drum brake system shown is worn on the top and the secondary shoe is worn on the bottom. Which of these could be the cause?
Weak hold-down springs Explanation: Weak return springs or a seized parking brake cable can cause excessive, but even brake shoe wear. A seized wheel cylinder piston will not apply one of the brake shoes causing the described wear. The correct answer is B.
3) A vehicle pulls to the left during braking and pulls right without braking. This could be caused by:
a collapsed right front brake hose. Explanation: Unequal tire pressure will cause a pull to one side with or without braking. A failed master cylinder will not cause a pull. A seized left front caliper will cause a pull to the right during braking. A collapsed right front brake hose may trap pressurized fluid between the hose and the caliper piston causing a pull to the right without brake application. The collapsed hose may restrict fluid flow to the caliper piston when the brakes are applied, causing a pull to the left. The correct answer is C.
12) A disc brake caliper should be replaced if it has:
contaminated brake fluid. Explanation: Seized caliper bolts, a damaged caliper mounting bracket or a leaking copper washer can all be replaced without caliper replacement. A caliper with contaminated fluid may have damaged rubber components and should be replaced. The correct answer is C.
23) This question is not like the other questions on the test. It uses the word EXCEPT. Read the question carefully before choosing your answer.An ABS hydraulic control unit (HCU) was replaced on a vehicle. The technician may have to perform all of these EXCEPT:
re-adjust the brakes. Explanation: The HCU and brake system should be purged of air for proper operation. The technician should verify the proper operation of the ABS. Re-adjustment of the brakes is not required as part of HCU replacement. The answer to the question is C.
