ASE (Entry level technician prep) - Brakes A5

A spongy brake pedal on a vehicle with 4-wheel disc brakes with a longer than normal travel indicates which of the following? a. Air in the hydraulic system b. Caliper piston seized c. Parking brake out of adjustment d. A faulty power booster

A. Air in the hydraulic system is the only choice that creates a spongy pedal.

This question 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. A vehicle has a very erratic brake pulling concern while applying the brakes. All of the following items could cause this erratic pull EXCEPT: a. Excessive tire pressure b. Four-wheel alignment c. Seized caliper piston on the other side d. Steering gear problem

A. Excessive tire pressure is the exception because this fault will cause tire wear but not a pull. Low or uneven tire pressure can cause a pull.

13. A vehicle comes in with a complaint of excessive pedal travel before the brakes apply. Technician A says the master cylinder pushrod adjustment is incorrect. Technician B says the cause is a faulty residual pressure check valve admitting air. Who is right? a. A only X b. B only c. Both A and B d. Neither A nor B

A. Technician A is right because if the master cylinder pushrod is too short that will be a delay in application. Technician B is wrong because a faulty residual check valve if used will cause a spongy pedal due to the ingress of air.

16. When performing a vacuum booster function test, you should begin by pumping the brake pedal several times _______________. a. with the engine off b. with the engine running c. with the vacuum hoses removed d. while driving the vehicle slowly

A. The engine must be off to deplete the vacuum reservoir to test the booster.

20. The front wheel bearings are being adjusted. Technician A says you torque the adjusting nut to a specified torque and back off the nut till it lines up with the hole and install the cotter pin. Technician B says backing off the castle nut will cause the bearing to overheat. Who is right? a. A only b. B only c. Both A and B d. Neither A nor B

A. You torque an adjusting nut to a specified torque and back off the nut till it lines up with the hole and install the cotter pin. Technician B is wrong because backing off the castle nut will not cause the bearing to overheat.

Quiz:A5 Question 3 There are signs of paint removal and peeling on the power brake booster right below the master cylinder. The cause of this could be: A) A leaking secondary cup on the primary piston. B)A defective diaphragm in the brake booster. C)A leaking secondary cup on the second piston. D)Fuel being drawn into the booster by the vacuum.

Answer A is correct! A leaking secondary cup on the primary piston could cause an external leak at the master cylinder. Because brake fluid tends to destroy paint, the peeling paint could be a good indication of a brake fluid leak.

Quiz:A5 Question 5 A vehicle pulls to the left during a brake application. The cause of the problem could be: A)The right front brake linings are contaminated with grease. B)The piston is seized in the right front brake caliper. C)The master cylinder pistons are swollen from contaminated fluid. D)The secondary compensating port is plugged in the master cylinder.

Answer B is correct! The direction a vehicle pulls toward during the application of brakes is the side of the vehicle that has less braking power. If something on the right side were causing the brakes to drag or grab, the vehicle would tend to pull to the side with less braking power on the left side.

Quiz:A5 Question 2 A vehicle has no brake pedal free play. This problem may cause: A) a low brake pedal. B)pressure build-up and dragging brakes. C)a spongy brake pedal. D)fluid leaking past the primary piston cups.

Answer B is correct! Without some free play, the brakes may not fully unapply and may cause brake dragging.

Quiz:A5 Question 4 When removing the master cylinder, all of the following steps must be performed EXCEPT: A) Relieve any vacuum boost pressure (if equipped with power brakes). B)Plug the ends of the brake lines to prevent fluid loss. C)Disconnect the float level sensor. D)Drain the master cylinder.

Answer D is correct! All of the answer choices need to be completed prior to removing the master cylinder. Draining the master cylinder of fluid is not something that must be done. If it is done thef luid is removed only after the lines have been disconnected and capped. Fluid should not run out of the master cylinder while it's being removed so it is easier to empty the cylinder on a bench.

A5 Question 1 The brake pedal is low and spongy; all brake adjustments have been completed according to specifications. The cause of the problem could be: A) Binding pedal linkage. B)Dented brake line. C)Plugged compensating port. D)A weak hydraulic hose.

Answer D is correct! Binding pedal linkage would cause a hard pedal and perhaps an effective brake system. This is also true for a dented brake line. A plugged compensator port may cause dragging brakes. A weak hydraulic brake hose could cause a spongy pedal. As the pressure builds in the system, the hose may expand and not relay the pressure to the brake units.

11. 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? a. A only b. B only c. Both A and B d. Neither A nor B

B. 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.

The ABS (antilock brake system) amber light does not go off after the engine is started. Technician A says a parking brake not fully released could be the cause. Technician B says when this happens the brakes will operate like a normal non-ABS brake system. Who is right? a. A only b. B only c. Both A and B d. Neither A nor B

B. If the amber light is on it indicates an ABS fault and the system will revert to regular brake operation without ABS. Technician A is wrong because the parking brake only affects the RED Brake Light not the amber.

2. 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? a. A only b. B only c. Both A and B d. Neither A nor B

B. 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 conditions can cause brake pedal fade? a. Seized wheel cylinder piston b. Brake drum machined beyond its limit c. Leakage past the master cylinder cups d. Air in the hydraulic system

B. The greatest drawback of drum brakes is that they are susceptible to fade. Brake fade is loss of stopping power that occurs when excessive heat reduces friction between brake shoe linings and drum. There are four types of brake fade. Mechanical fade occurs when the brake drum gets so hot it expands away from the brake linings. If the brake drum is machined beyond its limit the contact surface is further from the brake shoes and they move outward to maintain contact with the drum, causing the brake pedal to drop toward the floor as additional brake fluid moves into the hydraulic system. The other 3 choices would not cause brake fade.

21. The ABS (antilock brake system) and TRACTION OFF indicator lights remain ON with the engine running. Technician A says to check for ABS or TCS (traction control system) diagnostic trouble codes. Technician B says you can check for ABS or TCS blink codes by connecting two pins of the DLC (Data Link Connector). Who is right? a. A only b. B only c. Both A and B d. Neither A nor B

B. This is the standard process by many OEMS when a new rotor is installed. Technician A is wrong because recalibration is not required for these sensors.

. A power assist brake booster push rod that is to short will cause which of the following? a. Excessive brake drag b. Brake system to be inoperative c. Excessive brake pedal travel d. Brake light is illuminated

C. A short push rod length will have to travel farther for contact and result in excessive pedal travel

22. A wheel speed sensor is being diagnosed using the OEM (original equipment manufacturer) diagnostic scan tool. Technician A says to verify wheel speed sensor operation, compare all four wheel speed sensor outputs to vehicle speed on the data list. Technician B says the wheel's direction of rotation can be verified by looking at the wheel direction on the scan tool data list. Who is right? a. A only b. B only c. Both A and B d. Neither A nor B

C. Both technicians are correct.

5. Technician A says the vacuum supply test involves inspecting the vacuum supply hose for kinks. Technician B says the test involves checking the level of vacuum supplied by the engine or vacuum pump. Who is right? a. A only b. B only c. Both A and B d. Neither A nor B

C. Both technicians are correct.

9. Technician A says a defective wheel or axle bearing can make a growling or rumbling noise. Technician B says a defective wheel displays looseness or excessive play in the steering wheel especially while driving over rough road surfaces. Who is right? a. A only b. B only c. Both A and B d. Neither A nor B

C. Both technicians are correct.

17. On a bearing that has been shock loaded, the race (cup) of the bearing can be dented. What is this type of bearing failure called? a. Spalling b. Arcing c. Brinelling d. Fluting

C. Brinelling is defined as indentations in the race caused by impact loads or vibrations.

3. The brakes are being bled on an older vehicle equipped with a quick take up valve in the master cylinder. Technician A says the quick take up valve must be depressed. Technician B says the brakes on this vehicle cannot be bled. Who is right? a. A only b. B only c. Both A and B d. Neither A nor B

D) Both technicians are wrong. The brakes on quick take up systems use the same bleeding procedure as those without this valve.

9. This question 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: a. Brake adjustment b. Loose wheel bearing c. Low brake fluid d. Seized caliper piston

D. A seized caliper piston could cause the pedal to be high with reduced braking power.

A vehicle with disc/drum brakes requires excessive brake pedal effort to stop. The brake pedal is firm when applied. While starting the engine with the brakes applied, the pedal does not go down slightly. Technician A says excessive brake pedal freeplay could be the cause. Technician B says air trapped in the hydraulic system could be the cause. Who is right? a. A only b. B only c. Both A and B d. Neither A nor B

D. Both technicians are wrong because the problem is in the power booster. Excessive freeplay delays application and air in the hydraulic system will cause a spongy pedal.

14. With the brakes applied on a vehicle with power brakes, the pedal moves down slightly when the engine is started. Technician A says the cause could be a leaking power brake booster diaphragm. Technician B says the cause could be a stuck closed residual check valve in the hose from the intake manifold to the power brake booster. Who is right? a. A only b. B only c. Both A and B d. Neither A nor B

D. Both technicians are wrong because this is how power brakes are supposed to operate

7. The rear brake linings are soaked with axle grease but still have a lot of lining left on them. Which is the correct way to service these brakes? a. Replace the brake linings b. Wash in hot, soapy water and dry. c. Clean with approved cleaner and reuse d. Repair leak and replace brake linings

D. The leak must be repaired before the linings are replaced.

On a car with a drum/disc system, the front brakes lock up on light pedal application. This problem could be caused by a bad: a. Residual check valve b. Proportioning valve c. Pressure differential switch d. Metering valve

D. The metering valve controls the pressure to the front disc brakes on a combination system and if defective can allow too much pressure causing a lock-up. The other choices will not do this.

1. A spongy brake pedal may be caused by: a. ABS Diagnostic Trouble Code set b. Frozen caliper piston c. Defective metering valve. d. Air in hydraulic system

d / Air causes a gap in the hydraulic fluid flow because the fluid has to compress the air before it can apply the piston. This delay causes the spongy feel. The other choices do not affect this concern