ASE A5 Brakes Practice Test - Section 3- Disc Brake Diagnosis and Repair Questions and answers

ASE A5 Brakes Practice Test - Section 3- Disc Brake Diagnosis and Repair Questions and answers This question is not like the others. It has the word EXCEPT. For this question, look for the choice that could NOT cause the described situation. Read the entire question carefully before choosing your answer. All of these would cause a low brake pedal, EXCEPT: Seized caliper piston d - A seized caliper piston could cause the pedal to be high with reduced braking power A spongy brake pedal on a vehicle with 4-wheel disc brakes with a longer than normal travel indicates which of the following? Air in the hydraulic system Air in the hydraulic system is the only choice that creates a spongy pedal. . A vehicle with 4-wheel disc brakes has a brake squeal. Technician A says a defective proportioning valve could be the cause. Technician B says disc brake squeal is often caused by movement of the disc brake pad during braking. Who is right? B only - Disc brake squeal is often caused by movement of the disc brake pad during braking. To reduce disc brake squeal, all mating surfaces of the brake should be clean and lubricated. Always use OEM recommended clips and anti-squeal shims. To further reduce noise, do not machine a disc brake rotor more than absolutely necessary. Technician A is wrong because the proportioning valve only affects brake lockup and is not used on 4-wheel disc brakes only on disc/drum combinations. On a car with single piston floating caliper disc brakes, the disc brake pad between the caliper piston and the rotor is badly worn. The other brake pad is slightly worn. Technician A says excessive rotor run out could be the cause. Technician B says insufficient clearance between the pads and caliper slider could be the cause. Who is right? B only - Insufficient clearance between the pads and caliper slider causes the slider not to move and only applies one brake pad causing only that pad to wear. Technician A is wrong because excessive rotor runout will cause brake pulsations with no effect on wear. Which of the following problems would result in reduced brake pedal travel? Piston frozen in the caliper - Piston frozen in the caliper is the only choice that would cause reduced brake travel. If the piston is seized, you cannot push the fluid, resulting in reduced brake travel. Air in the hydraulic system and low brake fluid level will result in a spongy pedal and loose wheel bearings will cause a pull. What device used on 4-wheel disc brakes is being shown in the above figure? Self-adjuster The parking brake performance test on a vehicle with 4-wheel disc brakes must be performed with the vehicle facing a. Uphill b. Downhill c. Both A and B d. Neither A nor B Both A and B This is correct because brakes are checked in both an uphill and downhill vehicle facing position. The first step in brake pad service is which of the following? Remove some fluid from master cylinder - You must remove some fluid to prevent damage from overflow when you push in the caliper pistons to remove the brake pads. The front rotor needs to be replaced so the caliper must be removed. What should you do with the caliper after removing the retaining bolts? . Hang it on a piece of wire b - Hanging the caliper on a piece of wire preserves the brake line and puts it out of the way for the repair without disturbing the hydraulic system. All of the other choices are not appropriate or correct. A caliper piston seal is being removed from its bore. Which of the following tools should be used to perform this task? Wooden pick - The wooden pick is the only tool in the answer options that will not damage the bore Two technicians are discussing how to remove a caliper piston. Technician A says to use compressed air. Technician B says to use a large C-clamp. Who is right? A only - Use extreme care when removing a caliper piston using compressed air. The pressure applied can force the piston out of the caliper with tremendous force. The disassembly of a caliper is being described. Technician A says after piston removal and a thorough cleaning and inspection, a new square cut O-ring should be installed in the groove of the caliper bore. Technician B says to lubricate the caliper piston with clean transmission fluid, the caliper piston is then pushed into the caliper bore. Who is right? A only - Technician A states the standard procedure used by all manufacturers. Technician B is wrong because lubricate the caliper piston with clean brake fluid not transmission fluid. . Technician A says a steel piston should be cleaned with sandpaper to remove rust. Technician B says brake assembly fluid or clean brake fluid should be used to lubricate the caliper pistons before installing in the caliper. Who is right? . B only - Brake assembly fluid or clean brake fluid is the best fluid to use when assembling a caliper. Technician B is wrong because care should be taken when cleaning steel pistons. Use crocus cloth to remove any surface staining. Do not use sandpaper, emery cloth, or any other substance that may remove or damage the chrome surface finish. (Text page 1132) Which of the following is critical for the assembly of a single piston floating caliper? Clearance between the slider and caliper body - If the clearance is too small the slider will stick and cause premature pad wear The front rotor thickness variation (parallelism) is being measured. Technician A says you use a feeler gauge to make the measurement. Technician B says a dial indicator is used to make the measurement. Who is right Neither A nor B - Both technicians are wrong. A special micrometer or digital readout rotor micrometer is used, which is an accurate tool when measuring a rotor. Both fractional inches and metric millimeters are generally available. Two technicians are explaining how to service an aluminum metal matrix composite alloy rotor, when resurfacing is not used. Technician A says servicing these rotors is slightly different from cast-iron rotors. Technician B says you must remove the dark transfer layer on the rubbing surface anytime the rotor is removed. Who is right? A only Technician A is right because these rotors are serviced slightly different from cast-iron rotors. Technician B is wrong because dark transfer layer on the rubbing surface does not harm rotor performance and should not be removed unless the rotor needs to be machined due to being warped. The device shown in the above Figure is used when machining a brake rotor. Which of the following functions does it perform? Improves the quality of the machined surface a - This is a rubber damper that silences or reduced vibrations resulting in a smoother cut. The other choices do not apply. Two technicians are discussing the machining of a brake rotor. Technician A says OEM (original equipment manufacturers) like GM and others prefer the off-car form of rotor machining. Technician B says to check that the rotor is mounted correctly, loosen the retaining nut, turn the rotor one-half turn (180°), and retighten the nut and make another scratch cut. Who is right? B only b - Technician B is correct because this is the correct process for on or off car machining. Technician A is wrong because OEMs prefer the ON-CAR form of rotor machining. Two technicians are discussing the wear indicator shown in the above illustration. Technician A says it causes a light scraping or "chirping" noise when the brakes are not applied when the pads are worn down. Technician B says a lack of lubrication on the back of the disc brake pads can cause brake noise. Who is right? c. Both A and B c - Both technicians are correct Which of the following is the MOST likely cause of a pulsating brake pedal? Excessive rotor thickness variation - Thickness variation will cause lateral runout, which results in brake pulsations. The other choices will not cause a pulsating brake pedal