Brakes
Typical maximum rotor thickness variation (parallelism) specifications are _____________.
0.0003 to 0.0005 in. (0.008 to 0.013 mm)
After a non-drive-wheel bearing has been properly adjusted, the wheel should have how much end play?
0.001 to 0.005 in.
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)
Disc brake pads can reach temperatures as high as _________.
1,800 F
The backing plate should be replaced if the shoe contact areas (pads or ledges) are worn more than __________.
1/16 in. (2 mm)
The usual maximum pressure that should be used when pressure bleeding a brake system is ______.
30PSI
Usual maximum pressure that should be used when pressure bleeding a brake system is?
30PSI
A typical drum brake backing-plate has how many shoe support pads (also called ledges)?
6
What is the color of the antilock brake system (ABS) warning lamp?
Amber
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
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?
Both
Two technicians are discussing a floating-type disc brake caliper. Technician A says that if the caliper slides are corroded, one pad may wear more than the other pad on the same wheel brake. Technician B says that if a caliper slide is corroded, reduced braking may occur. Which technician is correct?
Both
Two technicians are discussing a problem where the brake pedals travels to far before the vehicle starts to slow. Tech A says that the brakes may be out of adjustment. Tech B says that one circuit from the master cylinder may be leaking or defective. Who's correct?
Both
Two technicians are discussing differentials. Technician A says all differentials are vented. Technician B says that a clogged vent can cause the rear axle seal to leak. Which technician is correct?
Both
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
All of the following are specified by the FMVSS 135 except ________________.
Brake noise level
Which one of these sends an electrical signal to the antilock brake control module?
Brake pedal position sensor
The bearing grease most often specified is rated NLGI __________________.
#2
Old brake shoes are often returned to the manufacturer when new friction material is installed. These old shoes are usually called the ______________.
Core
Air in the lines will cause what type of problem?
Low spongy brake pedal
Which Greek letter is used to represent the coefficient of friction?
Mu (μ)
Brake pads and linings that use synthetic material such as aramid fibers instead of steel are usually referred to as_____________.
NAS
The lower the Ra of a rotor, the _______ the surface.
Smoother
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?
Tech B
If a vehicle is equipped with antilock brakes, this means that __________ .
The vehicle will be able to be steered during hard braking
The lowest level of copper in brake friction material is shown on the leaf mark as________.
Three leafs
A hubless brake drum cannot be machined because it cannot be held in a lathe.
False
Air in the lines will causes what type of problem
Low spongy brake pedal
Which part of the drum brake shoe contacts the ledges on the backing plate?
Nib
Vacuum is applied where during vacuum bleeding?
At each wheel brake bleeder valve
Vacuum is applied where during vacuum bleeding?
At each wheel brake bleeder valve.
The location of the anchor pin is different for dual-servo and non-servo brakes, where is the anchor located on non-servo brakes?
At the bottom of the backing plate
Dual-servo brakes use different lengths brake shoes. Why does the shoe with the longer lining go to the rear?
Because of the stopping energy needed in reverse, and because the greater amount of heat and pressure the secondary shoe receives
When replacing a master cylinder, what should be done before installing it back into the car?
Bench bleed the master cylinder.
As brake fluid ages, what happens?
Boiling temperature decreases
A vehicle is hoisted during routine service and the service technician discovers that the left front wheel does not turn when force is applied. Technician A says that the hoist (lift) pads could be against the left front tire. Technician B says that the disc brake caliper piston stuck in the bore is the most likely cause. Which technician is correct?
Both
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?
Both
Brake fluid provides lubrication to the components in the hydraulic system. Tech A states that brake fluid also absorbed moisture. Tech B says that it is important property of brake fluid so the lines will not freeze in cold weather. Who is correct?
Both
Tech A says that some proportioning valves are one part and used to control both rear brakes. Tech B says that some proportioning valves are two parts, one for each rear wheel
Both
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
Technician A says that a lack of lubrication on the back of the disc brake pads can cause brake noise. Technician B says that pads that are not correctly crimped to the caliper housing can cause brake noise. Which technician is correct?
Both
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
Technician A says that disc brake pads should be replaced when worn to the minimum allowable thickness. Technician B says the pads should be removed and inspected whenever there is a brake performance complaint. Which technician is correct?
Both
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
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
Technician A says that many rear disc brake caliper pistons must be turned to retract before installing replacement pads. Technician B says that some vehicles equipped with rear disc brakes use a small drum brake as the parking brake. Which technician is correct?
Both
Technician A says that many vehicle manufacturers recommend that wheel cylinders not be honed because of the special surface finish inside the bore. Technician B says that some experts recommend that the wheel cylinders be replaced every time the brake linings are replaced. Which technician is correct?
Both
Technician A says that riveted disc brake pads are often quieter than bonded disc brake pads. Technician B says integrally molded disc brake pads are molded into holes in the steel backing of the pads. Which technician is correct?
Both
Technician A says that self-adjusters used on most drum brakes work when the brakes are applied, then release while traveling in reverse. Technician B says that some adjusters can over adjust if the brake drums are hot. Which technician is correct?
Both
Technician A says that silicone brake grease can be used to lubricate the shoe contact ledges. Technician B says that synthetic brake grease, lithium brake grease, or antiseize compound can be used as a brake lubricant. Which technician is correct?
Both
Technician A says that some proportioning valves are one part and used to control both rear brakes. Technician B says that some proportioning valves are two parts; one for each rear wheel brake.
Both
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
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
Technician A says that the brake fluid level should not be filled higher than the "MAX" level line to allow room for expansion when the brake fluid gets hot. Technician B says that the brake system should be checked for leaks or worn disc brake pads if the brake fluid is low. Which technician is correct?
Both
The rear wheels lock up during hard braking. Tech A says that a defective metering valve could be the cause? Tech B says that a defective proportioning valve could be the cause? Who is correct?
Both
Two technicians are discussing a problem where the brake pedal travels too far before the vehicle starts to slow. Technician A says that the brakes may be out of adjustment. Technician B says that one circuit from the master cylinder may be leaking or defective. Which technician is correct?
Both
Two technicians are discussing master cylinders. Technician A says that it is normal to see fluid movement in the reservoir when the brake pedal is depressed. Technician B says a defective master cylinder can cause the brake pedal to slowly sink to the floor when depressed. Which technician is correct?
Both
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
Electric adjustable pedals operate___.
Both accelerator and brake pedal
What part(s) should be replaced when servicing a wheel bearing on a non-drive wheel?
Both the grease seal and the cotter key (cotter pin)
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
The differential cover must be removed before removing the rear axle on which type of axle?
C-Lock
Drum brake shoes __________________________.
Can have riveted linings Can have bonded linings Can have one shoe that is longer than the other on the same wheel brake
Brake shoes return springs need to be inspected for what?
Coils touching together Make a thud sound when dropped Distortion
The function of the wheel cylinder is to?
Convert hydraulic pressure into a mechanical force at the brakes
Most manufacturers recommend that brake parts should be cleaned with ____________.
Denatured Alcohol
Dual-servo brakes have brake shoe linings that are...
Different lengths
Used brake fluid should be _____________.
Disposed of properly according to State and local laws
The type of brake fluid most often recommended by vehicle manufacturers is _______.
Dot 3
The two types of flares used on brake lines are _______________.
Double Flare and ISO
Most sealed bearings used on the front wheels of front-wheel-drive vehicles are usually which type?
Double row ball bearings
A typical pedal position (BPP) sensor/switch is ________.
Electrically normally open
How much brake fluid is in a typical master cylinder reservoir?
Enough to allow all brakes to be completely worn
A non-drive-wheel bearing adjustment procedure includes a final spindle nut tightening torque of ___________.
Finger tight
A four piston caliper is used in what type of caliper design?
Fixed
Which type of disc brake caliper may leak brake fluid more often?
Fixed
Which type of vehicles most often do not use metering valves?
Front Wheel drive
Air in the brake hydraulic system can cause all except ___________.
Hard brake pedal
Two types of flares used in brake lines are?
ISO and Double flare.
Why is copper being reduced in brake friction materials?
It can effect life in rivers and streams
The amount of asbestos in brake friction material is being restricted because______.
It is a health hazzard
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)
A quick take-up master cylinder is required when what type of caliper design is used on a vehicle?
Low-drag
Brake fade can occur due to_______.
Mechanical Fade Gas Fade Water Fade
The button on the __________ valve should be held when pressure bleeding the brakes.
Metering
The button on the ___________ valve should be held when pressure bleeding the brakes.
Metering
The button on the _______________ valve should be held when pressure bleeding the brakes.
Metering
A combination valve could include__________________.
Metering and proportioning valves Proportioning and pressure-differential valves Proportioning, metering, and pressure-differential valves Any of the above depending on the make and model of the vehicle
Rotor finish is measured in _______________________.
Microinches
Technician A says a pull to the right during braking could be caused by a defective metering valve. Technician B says a pull to the left could be caused by a defective proportioning valve. Which technician is correct?
Neither
Technician A says that all vehicles equipped with rear disc brakes use a parking brake that is integrated in the caliper. Technician B says that all vehicles equipped with rear disc brakes use a small drum brake inside the rear rotor for a parking brake. Which technician is correct?
Neither
Technician A says that the brake pedal should be depressed with as much force as possible during the normal bleeding procedure. Technician B says that the brake pedal should be pumped rapidly during this manual bleeding procedure to force the air down toward the bleeder valve(s). Which technician is correct?
Neither
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 lining should always be placed toward the front of the vehicle. Which technician is correct?
Neither
The master cylinder is able to move about how much brake fluid during each brake application?
One teaspoon
Brake fluid pressure is measured in what unit?
PSI
Disc brakes use replaceable friction material called __________.
Pads
What type of binder is used in all brake friction materials?
Phenolic resin
The brake bleeding procedure usually specified for a rear-wheel vehicle with a dual split master cylinder is _________________.
RR,LR,RF,LF
Which lining does most of the braking on a dual-servo brake?
Rear (rearward facing)
Slots are often used in brake pads because they______.
Reduce brake fade
What is the purpose of any brake repair?
Restore new-like performance
What part in the master cylinder helps keep air from contacting the brake fluid yet allows the fluid level to drop as the disc brakes wear?
Rubber diaphragm or floating disc
What can the driver do to reduce the possibility of brake fade caused by heat?
Select lower transmission gear
Drum brakes use replaceable friction material called ________.
Shoes
What part causes the disc brake caliper piston to retract when the brakes are released?
Square cut o-ring
A typical disc brake caliper overhaul (OH) kit usually includes what parts?
Square cut o-ring seal and dust boot
What seals a bleeder valve?
Tapered end
Which type of automotive bearing can withstand radial and thrust loads, yet must be adjusted for proper clearance?
Tapered roller bearings
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?
Tech A
An owner of a vehicle equipped with ABS brakes complained that whenever he tried to stop on icy or slippery roads, the brake pedal would pulse up and down rapidly. Technician A says that this is normal for many ABS units. Technician B says that the ABS unit is malfunctioning. Which technician is correct?
Tech A
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?
Tech A
Technician A says that glycol-based brake fluid causes the seals to swell slightly. Technician B says the DOT 5 (silicone-based) brake fluid causes rubber seals to swell slightly. Which technician is correct?
Tech A
The primary brake circuit fails due to a leak in the lines, leaving the rear section of a dual split master cylinder. Technician A says that the driver will notice a lower than normal brake pedal and some reduced braking power. Technician B says that the brake pedal will "grab" higher than normal. Which technician is correct?
Tech A
Two technicians are discussing how to loosen bleeder valves. Technician A says that a shock is usually necessary to break the taper at the base of the valve. Technician B says to apply steady, loosening torque to the bleeder valve using a 6-point wrench. Which technician is correct?
Tech A
Two technicians are discussing ways of removing a caliper piston. Technician A says to use compressed air. Technician B says to use large pliers. Which technician is correct?
Tech A
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°, and retightened. Technician B says that the rotor is not warped. Which technician is correct?
Tech B
Technician A says that DOT 5 brake fluid can be added to DOT 3 brake fluid. Technician B says that it is wise to purchase brake fluid that is in metal rather than plastic containers. Which technician is correct?
Tech B
Technician A says that a power-assisted brake reduces stopping distances compared with a non-power-assisted brake system. Technician B says that the power-assisted brake system reduces the force that the driver must exert on the brake pedal. Which technician is correct?
Tech B
Technician A says that a steel piston should be cleaned with sandpaper to remove rust. Technician B says that the brake assembly fluid or clean brake fluid should be used to lubricate the caliper pistons before installing in the caliper. Which technician is correct?
Tech B
Technician A says that the tinnerman nuts are used to hold the brake drum on and 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?
Tech B
The automatic adjuster system uses a star wheel and a lever. Tech A says the star wheel adjuster is the same for both sides. Tech B says the star wheel adjuster is a right hand thread for one side , and a left hand for the other side. Who's correct
Tech B
The bleeder is opened at a caliper and no brake fluid flows out. Tech A says that this is normal and that brake fluid should not flow or drip out of any open bleeder valve. Tech B says that the vent port in the master cylinder may be blocked. Who's correct.
Tech B
The bleeder is opened at a caliper and no brake fluid flows out. Technician A says that this is normal and that brake fluid should not flow or drip out of an open bleeder valve. Technician B says that the vent port in the master cylinder may be blocked. Which technician is correct?
Tech B
The rear brakes lock up during a regular brake application. Technician A says the metering valve could be the cause. Technician B says that stuck front disc brake calipers could be the cause. Which technician is correct?
Tech B
The rear wheels lock up during hard braking. Technician A says that a defective metering valve could be the cause. Technician B says that a defective proportioning valve could be the cause. Which technician is correct?
Tech B
Two technicians are discussing bench bleeding a master cylinder. Technician A says that the front (nose end) of the master cylinder should be bled first. Technician B says that rear (brake pedal end) should be bled first. Which technician is correct?
Tech B
Two technicians are discussing drum brake self adjusters. Technician A says that a frozen starwheel adjuster can cause the brakes to lock up due to the adjusting lever being unable to move the adjuster causing the linkage to bind. Technician B says that some brakes self adjust when the brakes are applied rather than when released. Which technician is correct?
Tech B
Two technicians are discussing why the brake lines are coiled near the master cylinder on many vehicles. Technician A says that these coils help prevent moisture from flowing from the master cylinder to the calipers. Technician B says that they help prevent cracks that could be caused by vibrations. Which technician is correct?
Tech B
Two technicians are discussing why the brake lines are coiled near the master cylinder. Tech A says that is is to reduce moisture from getting into the master cylinder. Tech B says that helps prevent cracks that could be caused by vibrations. Who's correct?
Tech B
Two techs are discussing bench bleeding a master cylinder. Tech A says that the front(nose end) of the master cylinder should be bled first. Tech B says the rear(brake pedal end) should be bled first. Who's correct?
Tech B
An edge code reading for coefficient of friction is EF. This means______.
The coefficient of friction is higher when the brakes are hot
Brake shoes should be replaced when
The linings are worn within .060" inch of a rivet head Linings contaminated with oil or grease Linings contaminated with brake fluid
Which shoe is the primary shoe on a dual-servo brake system?
The one toward the front of the vehicle as well as the shoe with the short lining
The FMVSS 135 standards determine ____________.
The performance of the braking system
Non-servo brakes have brake linings that are...
The same length
The star wheel adjuster is turned when?
The shoes are released after stopping backwards
Why should brake calipers be supported by a wire during brake service and not allowed to hang by the flexible brake hose?
To help prevent damage to the brake hose
The major reason for brake pedal pulsation during braking is due to excessive rotor thickness variation.
True
If the brake pedal linkage is not adjusted correctly, brake fluid may not be able to expand back into the reservoir through the ________________ port of the master cylinder when the brakes get hot.
Vent port (Forward hole)
If the brake pedal linkage is not adjusted correctly, brake fluid may not be able to expand back into the reservoir through the ____________ port of the master cylinder when the brakes get hot.
Vent port (Forward hole)
What should be done before removing a brake drum?
Wash drum down with a water based cleaner
Which is not a recommended type of grease to use on brake parts?
Wheel bearing (chassis) grease
Flexible brake hose should be inspected for all of the following except:
Worn outer ribs
Flexible brake hose should be inspected for all of the following expect?
Worn outer ribs
Hydraulic fluid in a closed hydraulic system is
non-compressible
