Brakes

The component in the Figure is involved what procedure? a. Replacing sealed wheel bearing b. Replacing the front strut c. Replacing a ball joint d. Repacking a front wheel bearing

Correct answer A

Brake systems contain all of these components EXCEPT: A. Double wall steel tubing B. Double wall copper tubing C. Flare nuts D. High-pressure rubber tubing

Correct answer B-Copper tubing should never be used within the brake system. Copper corrodes easily which makes it a poor option. It also expands when subjected to high pressures.

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

Correct answer C-Both technicians are correct.

A short power assist brake booster push rod will lead to which of these? A. Illuminated brake light B. Excessive brake pedal travel C. Inoperative brake system D. Excessive brake drag

Correct answer B-The short push rod length has to travel farther to make contact. This leads to excessive pedal travel. The other complaints wouldn't occur as a result.

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

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

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

Correct answer 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? a. Air in the hydraulic system b. Caliper piston seized c. Parking brake out of adjustment d. A faulty power booster

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

Technician A is working on a vehicle that was brought in with excessive brake pedal travel. The technician believes there is most likely an issue with the hydraulic system. Technician B believes there is an issue with the lateral runout of the rotor. Which technician is most likely correct? A. Technician A B. Technician B C. Both Technicians D. Neither Technician

Correct answer A-Excessive brake pedal travel is a sign of low hydraulic fluid, air in the hydraulic system, and can be caused by some mechanical issues as well. It will not be caused by lateral runout, which would cause brake chattering or pulsing.

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

Correct answer 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.

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 b. B only c. Both A and B d. Neither A nor B

Correct answer 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.

A vehicle is equipped with a vacuum brake booster. It doesn't have power assist until the engine runs for a minute, then it begins to work normally. What is the most likely reason? A. Defective check valve B. Adjusted brake pedal push rod is too short C. Front brake disc is worn D. Engine requires a tune-up to produce a higher vacuum at idle speed

Correct answer A-The defective check valve causes a loss in vacuum when the engine is off. That's why the power assist begins to function properly after the engine runs. The other three answers wouldn't cause the same issues.

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

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

When you make the final adjustments to the drum brakes: A. The star adjuster should be adjusted until there is a slight drag on the drum. Then, it needs to be backed off until the wheel begins to spin freely. B. The star adjuster should be adjusted one full turn to back the shoes away from the drum. C. The star adjuster should be adjusted until a slight drag on the wheel occurs. D. The star adjuster should be adjusted until the shoes hold the wheel in place firmly. Then, it should be backed off until there's a drag on the wheel.

Correct answer A-You must adjust the star adjuster until there's a slight drag on the drum. Then you want to back it off until the wheel starts to spin freely. All the other answers are improper ways of adjusting drum brakes.

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

Correct answer 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.

Which of these can lead to brake pedal fade? A. Brake drum machined beyond its limit B. Air in the hydraulic system C. Seized wheel cylinder piston D. Leakage beyond the master cylinder cups

Correct answer A-the biggest downside of drum brakes is their susceptibility to fading. This loss of stopping power occurs when heat reduces the friction needed between the drum and shoe linings. Mechanical fading is when the drum gets too hot and expands away from the linings. If the drum is machined beyond its limit, the contact surface moves further from the shoes.

4-wheel disc brakes on a vehicle are causing brake squeal. Technician A believes it's a defective proportioning valve issue. Technician B believes it's caused by movement of the brake pad while breaking. Who is correct? A. Technician A B. Technician B C. Both technicians D. Neither technician

Correct answer B-Disc brake squeal is caused by the brake pad moving while braking. To reduce this, the mating surfaces need to be cleaned and lubricated. You also want to use OEM clips and anti-squeal shims. To further reduce the noise, do not machine the rotor more than needed.

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

Correct answer 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.

All of these might lead to a low brake pedal, EXCEPT: A. Loose wheel bearing B. Seized caliper piston C. Brake adjustment D. Low brake fluid

Correct answer B-Having a seized caliper piston leads to a high pedal. This also reduces braking power. The other three answers can lead to a low brake pedal.

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

Correct answer 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.

The ABS light doesn't go off after the engine starts. Technician A states that the parking brake is not fully released. Technician B states that the brakes can continue to operate like non-ABS brakes. Who is correct? A. Technician A B. Technician B C. Both technicians D. Neither technician

Correct answer B-If the amber light is on, it indicates that there is an ABS fault. The system reverts to regular brake operation without ABS. Technician A is wrong because the parking brake would only affect the red brake light.

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

Correct answer 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

Correct answer 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 front brake rotors and pads are being replaced on a vehicle equipped with a TCS (traction control system) and electronic stability control system (ESC). Technician A says the yaw rate and deceleration sensor should be recalibrated. Technician B says the new rotors should be indexed to the hub using a dial indicator for the least amount of runout. Who is right? a. A only b. B only c. Both A and B d. Neither A nor B

Correct answer 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.

You notice brake fluid in the engine. A possible cause of this leakage might be: A. Partially restricted air cleaner element B. Defective PCV valve with excessive restriction C. Defective one-way check valve in booster vacuum hose D. Defective vacuum hose to the brake booster

Correct answer C-A defective hose would not allow the fluid to enter the engine. The PCV valve vents the crankcase of blow by gases and isn't part of the braking system. The air cleaner also can't cause a brake fluid leak.

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

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

On ABS systems that have a high-pressure accumulator, this is depressurized by: A. pumping the brake pedal 10 times with the ignition switch on B. loosening the bleeder screw on the accumulator with the ignition switch on C. pumping the brake pedal 25 times with the ignition switch off D. loosening the front wheel bleeder screws with the ignition switch on

Correct answer C-An ABS with a high-pressure accumulator, you depressurize it by pumping the brake pedal 25 times while the ignition switch is off. Opening or loosening any part of the hydraulic system is dangerous because of the fluid pressure.

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

Correct answer C-Both technicians are correct.

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

Correct answer C-Both technicians are correct.

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

Correct answer C-Both technicians are correct.

The ABS and TRACTION OFF indicator lights stay on while the engine is running. Technician A says to check the TCS and ABS diagnostic trouble codes. Technician B says to check for TCS or ABS blink codes by connecting two pins of the DLC. Who is correct? A. Technician A B. Technician B C. Both technicians D. Neither technician

Correct answer C-Both techs are correct. Checking the diagnostic trouble codes is possible. It's also possible to check the blink codes with the DLC.

The wheel speed sensor is being diagnosed with an OEM diagnostic scan tool. Technician A says to verify the wheel speed sensor operation and compare all four wheel speed sensor outputs to the data list. Technician B says that the wheel's direction of rotation should be verified by looking at the direction on the scan tool data list. Who is correct? A. Technician A B. Technician B C. Both technicians D. Neither technician

Correct answer C-Both techs are correct. You can verify the wheel speed sensor operation while comparing the four-wheel outputs to the data list. You can also verify it by looking at the direction on the scan tool data list.

Brake rotors need to be refinished under all of these conditions EXCEPT: A. Slight scoring or heat spots B. Failure of lateral runout or thickness variation checks C. Installation of a new brake rotor D. Noticeable brake pulsation

Correct answer C-New brake rotors don't need to be refinished. Rotors should be refinished when there is scoring, heat spots, lateral runout, pedal pulsations or thickness variation.

The brake pedal starts to feel spongy and low even though all the adjustments have been made according to the specifications. What could be the cause of the problem? A. Dented brake line B. Binding pedal linkage C. Weak hydraulic hose D. Plugged compensating port

Correct answer C-The weak hydraulic brake hose causes a spongy pedal. The pressure can continue to build and the hose might expand, but not release the pressure to the brake units. Binding pedal linkage would lead to a hard pedal, which is also true for a dented brake line. The plugged compensator port leads to dragging brakes instead.

The lack of brake pedal free play on a vehicle might cause: A. Spongy brake pedal B. Low brake pedal C. Pressure build-up and dragging brakes D. Fluid leaking beyond the primary piston cups

Correct answer C-when there's no free play, the brakes can't disengage fully. This leads to the brakes dragging. The other situations wouldn't be caused by the lack of free play.

A restricted disc brake caliper hose might cause all of these EXCEPT: A. Poor stopping B. The vehicle pulls to the side under heavy braking C. Dragging brakes D. Brake pedal pulsation

Correct answer D-A restricted disc brake caliper hose won't cause pedal pulsation. Pulsation results from something loose in the system or by an unparallel rotor. All the other answers could occur.

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

Correct answer 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.

Brakes on an older vehicle with a quick take up valve in the master cylinder are being bled. Technician A believes that you must depress the quick take up valve. Technician B believes that the brakes can't be bled. Who is correct? A. Technician A B. Technician B C. Both technicians D. Neither technician

Correct answer D-Both of these techs are wrong. The brakes on quick take up systems use the exact bleeding procedure as systems without the valve. You don't need to do anything different.

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

Correct answer 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.

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

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

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

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

When you remove the master cylinder, you must take all these steps EXCEPT: A. Disconnect the float level sensor B. Plug the ends of the brake lines to prevent fluid loss C. Vacuum boost pressure with power brakes D. Drain the master cylinder

Correct answer D-Draining the master cylinder isn't required. If it needs to be done, the fluid can be removed after the lines are capped. Fluid will not run from the master cylinder while you remove it. Then, it's easier to empty once it's out.

Erratic brake pulling occurs on a vehicle when the brakes are applied. All of these could cause this problem EXCEPT: A. Double wall steel tubing B. Double wall copper tubing C. Flare nuts D. High-pressure rubber tubing

Correct answer D-Excessive tire pressure isn't going to cause the erratic pulling. It will lead to increased tire wear. If the vehicle has low or uneven tire pressure, there might be a pull.

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

Correct answer 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

Correct answer 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.