Aut150 Final Exam

Typical maximum rotor thickness variation (parallelism) specifications are ________.

0.0003 to 0.0005 in. (0.008 to 0.013 mm)

Most manufacturers specify that the friction surfaces of a rotor must be parallel to within ________.

0.0005 inch (0.013 mm)

Typical maximum rotor runout specifications are ________.

0.003 to 0.005 in. (0.08 to 0.13 mm)

Most brake experts and vehicle manufacturers recommend replacing brake lining when the lining thickness is ________.

0.060 in. (1.5 mm)

The backing plate should be replaced if the shoe contact areas (pads or ledges) are worn more than ________.

1/16 in. (2 mm)

The rear brakes should be inspected, and adjusted if necessary, if the parking brake requires more than ________.

10 clicks

A typical drum brake uses how many hold-down springs?

2

A typical drum brake backing-plate has how many shoe support pads (also called ledges)?

6

In a servo brake, the secondary shoe provides approximately what percentage of the total stopping power?

70

What is not included with a loaded caliper?

A replacement rotor

Automatic adjusters may be actuated by all of the following EXCEPT ________.

A. Cable B. Lever C. Air pressure --- D. Parking brake

When brake linings are replaced, the ________ should be inspected.

A. Camber angle of the suspension B. Condition of the wheel cylinders C. Both A and B D. Neither A nor B (idk)

Drum brake shoes ________.

A. Can have riveted linings B. Can have one shoe that is longer than the other on the same wheel brake C. Can have bonded linings D. All of the above are possible ----

When cleaning brake hydraulic parts, use ________.

A. Denatured alcohol B. Clean brake fluid C. Either A or B D. Neither A nor B (idk)

Why do many vehicle manufacturers recommend that brake fluid be changed regularly?

A. Old brake fluid can cause rust and corrosion of brake system components B. Brake fluid absorbs moisture over time C. The boiling point of the brake fluid decreases D. All of the above ----

In a typical integral rear disc brake caliper, the parking brake cable moves the ________.

A. Rotor B. Caliper C. Actuator screw D. Auxiliary piston (idk)

Technician A says that wheel cylinder dust boots keep dust and moisture out of the cylinder bore. Technician B says that it is normal for dust boots to allow a little seepage of fluid. Which technician is correct?

A. Technician A only B. Technician B only C. Both technicians A and B D. Neither technician A nor B (idk)

After assembling a drum brake, it is discovered that the brake drum will not fit over the new brake shoes. Technician A says that the parking brake cable may not have been fully released. Technician B says to check to see if both shoes are contacting the anchor pin. Which technician is correct?

A. Technician A only B. Technician B only C. Both technicians A and B D. Neither technician A nor B (idk)

Star-wheel adjuster installation is being discussed. Technician A says that the adjuster is the same for both the left and right sides of the vehicle. Technician B says the adjuster should be installed with the star wheel end of the adjuster facing toward the front of the vehicle. Which technician is correct?

A. Technician A only B. Technician B only C. Both technicians A and B D. Neither technician A nor B (idk)

Technician A says to use masking tape temporarily over the lining material to help prevent getting grease on the lining. Technician B says that grease on the brake lining can cause the brakes to grab. Which technician is correct?

A. Technician A only B. Technician B only C. Both technicians A and B D. Neither technician A nor B (idk)

The parking brake performance test must be performed with the vehicle facing ________.

A. Uphill B. Downhill C. Both A and B D. Neither A nor B (idk)

Automatic parking brake releases ________.

A. Use an electric solenoid B. Use a vacuum servo C. Both A and B .....

Most auxiliary drum parking brakes are located ________.

A. on the axle half-shaft B. on the front wheels C. on the transmission D. inside a rotor "hat" (idk)

Because brake fluid is hygroscopic, it ________.

Absorbs moisture

When manually adjusting brakes equipped with automatic adjusters, the ________ must be pushed or held out of the way.

Adjuster lever

A bulge on a brake hose is ________.

An indication of an internal leak

The shoe support pads ________.

Are lightly coated with silicone brake grease to minimize wear

A vehicle pulls to one side when braking. This could be caused by all of these EXCEPT ________.

Bad master cylinder

Although some calipers will fit either side of a vehicle, they should not be interchanged because the ________.

Bleeder valve will be in the wrong position

Technician A says that drum brakes can fail to slow the vehicle if driven through deep water. Technician B says that when drum brakes get hot, the brake pedal will drop because the drum expands away from the shoes. Which technician is correct?

Both Technicians A and B

Technician A says that starwheel adjusters use different threads (left and right handed) for the left and right sides of the vehicle. Technician B says that a pawl controls the teeth of the starwheel adjuster. Which technician is correct?

Both Technicians A and B

Technician A says that the anchor pin (shoe anchor) is used to hold one end of the primary and secondary shoe return springs. Technician B says that shoe anchor prevents the brake shoes from rotating with the drum when the brakes are applied. Which technician is correct?

Both Technicians A and B

Technician A says that the labyrinth seal (drum groove) helps to keep water from getting into a drum brake. Technician B says that only synthetic brake grease, lithium brake grease or anti-seize compound should be used as a brake lubricant. Which technician is correct?

Both Technicians A and B

Technician A says a parking brake equalizer may consist of a cable guide attached to a threaded rod. Technician B says a brake equalizer balances the force from the parking brake control. Which technician is correct?

Both technicians

Technician A says that all metal-to-metal contact areas of the disc brake system should be lubricated with special brake grease for proper operation. Technician B says that the lubrication helps reduce brake noise (squeal). Which technician is correct?

Both technicians

Technician A says that an electric parking brake (EPB) uses an electric motor to pull on the parking brake cable. Technician B says that some electric parking brake systems use a computer controlled motor attached to the caliper. Which technician is correct?

Both technicians

Technician A says that disc brake pads showing cracks in the lining material should be replaced. Technician B says the pads should be removed and inspected whenever there is a brake performance complaint. Which technician is correct?

Both technicians

Technician A says that disc brakes are self adjusting and the brake pedal height should not become lower as the disc brake pads wear. Technician B says that as the disc brake pads wear, the level of brake fluid in the master cylinder reservoir drops. Which technician is correct?

Both technicians

Technician A says that the parking brake hand lever can turn on the red brake warning lamp. Technician B says that a foot-operated parking brake can turn on the red brake warning lamp. Which technician is correct?

Both technicians

Technician A says the parking brake is controlled by a lever. Technician B says a pedal may be used. Which technician is correct?

Both technicians

Two technicians are discussing parking brake systems including those that mechanically actuate the rear disc brake caliper. Technician A says that the calipers are self-adjusting. Technician B says that the actuating cables are adjustable at the equalizer. Which technician is correct?

Both technicians

Two technicians are discussing the reason that the brake fluid level in the master cylinder drops. Technician A says that it may be normal due to the wear of the disc brake pads. Technician B says that a low brake fluid level may indicate a hydraulic leak somewhere in the system. Which technician is correct?

Both technicians

Uneven disc brake pad wear is being discussed. Technician A says the caliper piston may be stuck. Technician B says the caliper may be stuck on the slides and unable to "float." Which technician is correct?

Both technicians

A disc brake rotor is being installed on a lathe for machining. During the setup a scratch test is performed. The scratch extended all the way around the rotor. Technician A says that the rotor should be loosened, rotated 180 degrees, and retightened. Technician B says that the rotor is not warped. Which technician is correct?

Both technicians A and B

Technician A says a poor engine ground connection can cause electricity to flow through wheel bearings, causing damage. Technician B says using chassis grease may result in premature bearing failure. Which technician is correct?

Both technicians A and B

Technician A says heat checking can be caused by numerous panic stops in rapid succession. Technician B says it can be caused by "riding" the brake pedal. Which technician is correct?

Both technicians A and B

Technician A says that a defective wheel or axle bearing often makes a growling or rumbling noise. Technician B says that a defective wheel or axle bearing often makes a noise similar to a tire with an aggressive mud or snow design. Which technician is correct?

Both technicians A and B

Technician A says that a disadvantage of drum brakes is that they require an adjusting mechanism to maintain the proper clearance between the shoe and drum. Technician B says that a disadvantage of drum brakes is that they pull the car to one side during braking under certain conditions. Which technician is correct?

Both technicians A and B

Technician A says that aluminum brake drums use cast iron friction surfaces. Technician B says that up to 0.030 in. (0.8 mm) should be left after machining a drum to allow for wear. Which technician is correct?

Both technicians A and B

Technician A says that most experts recommend replacing all drum brake hardware including the springs every time the brake linings are replaced. Technician B says that the starwheel adjuster must be cleaned and lubricated to assure proper operation. Which technician is correct?

Both technicians A and B

Technician A says that silicone grease can be used to lubricate the shoe contact ledges. Technician B says that synthetic brake grease, lithium brake grease, or anti-seize compound can be used as a brake lubricant. Which technician is correct?

Both technicians A and B

Technician A says that starwheel adjusters use different threads (left and right-handed) for the left and right sides of the vehicle. Technician B says that the threads and end caps of the adjusters should be lubricated with brake grease before being installed. Which technician is correct?

Both technicians A and B

Technician A says that the access hole for the starwheel adjuster may be in the brake drum web. Technician B says that the access hole for the starwheel may be found in the backing plate. Which technician is correct?

Both technicians A and B

Technician A says to use synthetic grease to lubricate the backing plate. Technician B says to use special lithium-based brake grease. Which technician is correct?

Both technicians A and B

Technician a says that the red brake warning light can be turned on if a difference in pressure is detected by the pressure differential switch. Technician B says that the red brake warning light can be turned on if the brake fluid level sensor detected low brake fluid level. Which technician is correct?

Both technicians A and B

Two technicians are discussing the machining of brake drums. Technician A says that most brake drums cannot be machined more than 0.060 in. oversize. Technician B says that brake drums on a common axle should be machined to within 0.010 in. of each other. Which technician is correct?

Both technicians A and B

Wheel bearings are being packed with grease. Technician A says to use grease that is labeled "GC." Technician B says to use grease with an NLGI number of 2. Which technician is correct?

Both technicians A and B

The greatest disadvantage of drum brakes is ________.

Brake fade

On a bearing that has been shock loaded, the race (cup) of the bearing can be dented. This type of bearing failure is called ________.

Brinelling

Before returning the vehicle to the customer the new brake pads should be ________.

Burnished

A type of anti-squeal shim made from a dampening material sandwiched between two layers of steel.

CLS

The outboard pad of a single piston caliper is pushed against the rotor by the ________.

Caliper body

Old brake shoes are often returned to the manufacturer when new friction material is installed. These old shoes are usually called the ________.

Core

Which of the following is NOT a part of a brake caliper assembly?

Cup seal

The type of brake fluid most often recommended by vehicle manufacturers is ________.

DOT 3

Anti-rattle spring clips ________.

Damp vibrations

Most manufacturers recommend that brake parts that are disassembled should be cleaned with ________.

Denatured alcohol

The rubber used in most brake system components will swell if exposed to ________.

Engine oil or ATF

The parking brake cable can be adjusted in most cases at the ________.

Equalizer

Hard spots in a brake drum are caused by ________.

Excessive heat and pressure

Use a screwdriver to remove caliper piston seals.

False

A non-drive-wheel bearing adjustment procedure includes a final spindle nut tightening torque of ________.

Finger tight

On most vehicles, the anti-rattle spring (strut spring) should be installed on the parking brake strut toward the ________ of the vehicle.

Front

Disc brakes ________.

Have self-adjusting ability

Cup expanders are used in some wheel cylinders to ________.

Hold the lips of the cups against the cylinder walls

The term that refers to a polyglycol based brake fluid's tendency to absorb moisture from the atmosphere.

Hygroscopic

Which one is not a form of drum distortion?

Lack of parallelism

Which of the following is NOT a characteristic of conventional brake fluid?

Lasts the life of the vehicle unless there is a leak

Which lining does most of the braking on a leading/trailing brake?

Leading (forward facing)

Air in the lines will cause what type of problem?

Low spongy brake pedal

A quick take-up master cylinder is required when what type of caliper design is used on a vehicle?

Low-drag

The chamfer on the inside edge of a brake drum usually indicates ________.

Maximum allowable inside diameter

Rotor finish is measured in ________.

Microinches

Technician A says the parking brake cable adjustment should be performed before adjusting the rear brakes. Technician B says the parking brake cable should allow for about 15 "clicks" before the parking brake holds. Which technician is correct?

Neither technician

Two technicians are discussing the construction of a single piston caliper. Technician A says that the fluid is retained by a piston seal fitted in a groove machined in the piston. Technician B says that the piston is held in the caliper by a lock ring. Which technician is correct?

Neither technician

Two technicians are discussing drum brake shoes. Technician A says that forward and rear-facing shoes are the same and can be installed in either position on any drum brake system. Technician B says that the darker color linings should always be placed toward the front of the vehicle Which technician is correct?

Neither technician A nor B

After a disc brake pad replacement, the brake pedal went to the floor the first time the brake pedal was depressed. The most likely cause was ________.

Normal operation

Single-piston type disc brakes are adjusted by ________.

Piston movement through the seal

When the brakes are released, the caliper pistons are retracted by ________.

Piston seals

The brakes on a dual-servo drum system are designated as ________.

Primary and secondary

On most drum brake systems, the parking brake lever and strut transfer the pulling force of the parking brake cable against the ________.

Primary shoe

Parking brake levers may be released by ________.

Pushing a spring-loaded button

Which lining does most of the braking on a dual-servo brake?

Rear (rearward facing)

If the parking brake will not hold on a hill or requires excessive lever movement always check and adjust the ________ before adjusting the parking brake cable.

Rear brake adjustment

The first step in brake pad replacement is ________.

Remove some fluid from the master cylinder reservoir

________ action uses drum rotation to force the brake shoe outward and wedge it tightly against the brake drum.

Self-energizing

Which friction lining compound is MOST likely to cause excessive rotor wear?

Semimetallic, Ceramic

Semimetallic brake pads are made by a process called ________.

Sintering

The lower the Ra of a rotor, the ________ the surface.

Smoother

Which is NOT a type of brake drum construction?

Solid composite

The caliper square cut seal may need to be pried out with a(an) ________.

Special tool

A typical disc brake caliper overhaul (OH) kit usually includes what parts?

Square-cut O-ring seal and dust boot

Which is NOT a bearing problem?

Stripping

Which type of automotive bearing can withstand radial and thrust loads, yet must be adjusted for proper clearance?

Tapered roller bearing

Technician A says some brake pads have tapered edges to prevent vibration. Technician B says pad wear indicators are required by law on all new vehicles. Which technician is correct?

Technician A

A "chirping" noise is heard while the vehicle is moving forward, but stops when the brakes are applied. Technician A says that the noise is likely caused by the disc brake pad wear sensors. Technician B says the noise is likely a wheel bearing because the noise stops when the brakes are applied. Which technician is correct?

Technician A only

Technician A says that brake drums on the same axle should be close to the same inside diameter for best brake balance. Technician B says that a brake drum may be cracked if it rings like a bell when tapped with a light steel hammer. Which technician is correct?

Technician A only

Technician A says that if the parking brake cable is adjusted too tight, the rear brakes may drag and overheat. Technician B says that the parking brake is adjusted properly if the cable is tight when in the released position. Which technician is correct?

Technician A only

Technician A says that when repairing brakes, it is a good practice to inspect the backing plate for a bent or cracked structure. Technician B says that the pads of the backing plate should be lubricated with heavy grease before installing new shoes. Which technician is correct?

Technician A only

Two technicians are discussing hard spots in brake drums. Technician A says the drum should be replaced. Technician B says the hard spots are caused by using riveted rather than bonded brake shoes. Which technician is correct?

Technician A only

A rear drum brake is being inspected. The primary shoe is not contacting the anchor pin at the top. Technician A says that this is normal. Technician B says that the parking brake cable may be adjusted too tight or is stuck. Which technician is correct?

Technician B only

Technician A says that a steel piston should be cleaned with sandpaper to remove rust. Technician B says that brake assembly fluid or clean brake fluid should be used to lubricate the caliper pistons before installing in the caliper. Which technician is correct?

Technician B only

Technician A says that a steel piston should have a greater piston-to-caliper bore clearance than a phenolic piston because the steel piston will expand when the brake fluid temperature increases during normal braking. Technician B says that the phenolic piston should have the greater clearance. Which technician is correct?

Technician B only

Technician A says that hard spots in a brake drum should be removed using a carbide-tip machining tool. Technician B says that the drum should be replaced if hard spots are discovered. Which technician is correct?

Technician B only

Technician A says that the tinnerman nuts used to hold the brake drum on should be reinstalled when the drum is replaced. Technician B says that a drum should be removed inside a sealed vacuum enclosure or washed with water or solvent to prevent possible asbestos dust from being released into the air. Which technician is correct?

Technician B only

Technician A says there are no brake lathes that can machine rotors on the vehicle. Technician B says drums may be removed from the vehicle to be machined. Which technician is correct?

Technician B only

Two technicians are discussing disc brake rotor service. Technician A says that the inner races (bearing cups) should be removed from the rotor before it is mounted on the lathe. Technician B says that a non-directional finish on the rotor surfaces can be obtained by using sandpaper. Which technician is correct?

Technician B only

Two technicians are discussing drum brake self-adjusters. Technician A says that some brakes self-adjust when the brakes are released when the vehicle is driven in reverse. Technician B says that some brakes self-adjust when the brakes are applied rather than when released. Which technician is correct?

Technician B only

When the pressure in a caliper is released, the piston is moved back in the cylinder by ________.

The action of the piston seal

As brake fluid ages, what happens?

The boiling temperature decreases

Mechanical fade is not a problem with disc brakes because _______

The brake rotor expands toward the brake linings as it heats up

On non-servo brakes, which shoe does most of the braking in during forward movement of the vehicle?

The leading shoe

The last two letters of a lining edge code reads EF. This means ________.

The lining has a higher coefficient of friction when hot than when cold

On the dual-servo braking system, which shoe does most of the braking during forward movement of the vehicle?

The secondary shoe

What part causes the disc brake caliper piston to retract when the brakes are released?

The square cut O-ring

Disc brakes have many advantages, some of which are listed below. Which of the following statements does NOT apply to disc brakes?

They are self-energizing

Which is NOT a part of a disc brake?

Tie rod

Rotors are vented ________.

To aid cooling

Rebuild or replace the caliper if the dust boot is damaged in any way.

True

Which is not a recommended type of grease to use on brake parts?

Wheel bearing (chassis) grease

All of the following statements pertaining to composite rotors are false EXCEPT:

a. composite rotors have a steel wear surface b. composite rotors have a steel center section and a caste iron wear surface ----- c. composite rotors always have drill holes in the wear surface d. composite rotors are made from carbon fiber

A type of brake hydraulic system found on most rear wheel drive cars and trucks.

dual split

The term used to identify the rubber found in brake systems.

elastomers

Which of the following is not a type of anti-friction bearings?

garter bearing

A type of brake fade which results in a decease in the brake pad friction coefficient and caused by excessive heat.

lining fade

Identify the term that is best described as a variation in the thickness of the rotor when measured at several places around its circumference.

parallelism

A type of caliper piston made from fibers and formaldehyde resin.

pheolic

A valve or switch found in brake systems that provides an electrical ground to illuminate a warning lamp when one part of the system experiences a line or component rupture or leak.

pressure differential

The passage found in a master cylinder that allows fluid to fill the area behind the piston at low pressure and subsequently fill the brake hydraulic system.

replenishing

Identify the term that is best described as an extreme form of rotor wear including grooves or an otherwise rough surface.

scoring

The process of fusing metal particles together, such as in semi-metallic brake pads, without melting the metal.

sintering

How does a bleeder valve seal?

tapered ends

Identify the term that is best described as a "side to side wobble of the rotor as it rotates".

total indicated runout

Terminology relating to the area that a caliper mounts and slides across during brake application

ways