Deck 50: Brake Systems

Question 1

If a master cylinder with a 1 inch bore is replaced with a cylinder with a three-quarter inch bore, the pressure in the brake lines will be higher when the same amount of brake pedal pressure is applied to each cylinder.

Answer 1

True

Question 2

Master cylinders are generally not overhauled in the field. They are replaced with new or rebuilt master cylinders.

Answer 2

True

Question 3

A brake line must be single-flared to provide a good seal at a joint or junction block.

Answer 3

False

Question 4

A brake fluid lamp will illuminate on the instrument panel if the fluid is contaminated and needs to be changed.

Question 5

Most manufacturers recommend changing the brake fluid periodically.

Question 6

All manufacturers recommend a specific sequence to follow when bleeding a vehicle's brakes.

Question 7

All master cylinders are made of cast iron.

Question 8

When the brakes are applied while the vehicle is moving forward, the weight of the vehicle
shifts toward the rear wheels.

Question 9

Vehicles built since 1976 have a center high-mounted stop lamp (CHMSL).

Question 10

Fully metallic linings require very high pedal pressure and tend to quickly wear out drums and rotors.

Question 11

If the front hydraulic circuit fails on a front/rear split brake system, the vehicle will lose 50 percent of its braking power.

Question 12

The fluid level in the reservoir for the rear drum brakes will drop significantly as the brake shoes wear down.

Question 13

Brake hoses are typically rigid steel lines used to transmit brake fluid pressure.

Question 14

Brake fluid serves as a lubricant for the parts of the hydraulic system and ensures smooth and even operation.

Question 15

Brake fluid must be able to flow freely at 500 degrees Fahrenheit (260 degrees Celsius) and at -104 degrees Fahrenheit (-76 degrees Celsius).

Question 16

All brake fluids are hygroscopic-that is, they readily absorb water.

Question 17

Asbestos has not been used in brake linings or pads since 2003.

Question 18

Power brakes are completely different than a standard hydraulic brake system, using different types of master cylinders, calipers, and hydraulic circuits.

Question 19

Translucent plastic brake fluid reservoirs eliminate the need to remove the fluid caps during a complete brake system inspection.

Question 20

Residual check valves are found only on vehicles with rear disc brakes.

Question 21

Technician A says a metering valve delays front braking until the rears are applied. Technician B says a proportioning valve controls rear brake pressure, especially during moderate stops. Who is correct?

A) A only
B) B only
C) both A and B
D) neither A nor B

Question 22

The power brakes in a vehicle are grabbing. Technician A checks for grease or oil on the brake shoe and pad linings. Technician B checks the fluid level in the master cylinder. Who is correct?

A) A only
B) B only
C) both A and B
D) neither A nor B

Question 23

Which of the following could most likely lead to brake hose failure?

A) incorrect brake fluid
B) stressing the hose during installation
C) extreme cold operation
D) all answers are correct

Question 24

The friction that is generated between the brake pads and rotors when the vehicle is descending a steep hill is called ______.

A) static
B) kinetic
C) heat
D) resistive

Question 25

Which of the following could cause an extremely hard brake pedal?

A) air in the system
B) excessively worn brake pads
C) use of the wrong fluid
D) a leaking diaphragm in the vacuum power booster

Question 26

While discussing quick take-up master cylinders, Technician A says this design is used with low-drag caliper pistons. Technician B says this design is only used on disc brake systems. Who is correct?

A) A only
B) B only
C) both A and B
D) neither A nor B

Question 27

Since _____, all cars have been required to have two separate brake systems.

A) 1957
B) 1967
C) 1977
D) 1987

Question 28

Factors that determine a vehicle's braking power are being discussed. Technician A says the coefficient of friction between the pad and rotor or shoe and drum is a factor. Technician B says heat dissipation from brake components is a factor. Who is correct?

A) A only
B) B only
C) both A and B
D) neither A nor B

Question 29

Dissipation of heat from the brake components is necessary to prevent brake ______.

A) chatter
B) fade
C) grab
D) shudder

Question 30

What type of power-assist unit uses pressure developed by an external pump, such as a power steering pump?

A) hydraulic-assist
B) vacuum-assist
C) ABS
D) ASC

Question 31

While manually bleeding a brake system, Technician A loosens all the brake bleeder screws at the same time. Technician B uses shop air to push the fluid and air through the lines and out the bleeder screws. Who is correct?

A) A only
B) B only
C) both A and B
D) neither A nor B

Question 32

When bleeding a dual diagonal split brake system, the bleeding sequence is usually _____.

A) LR-RR-RF-LF
B) RF-LF-LR-RR
C) RR-LF-LR-RF
D) LR-RF-RR-LF

Question 33

The purpose of the master cylinder is to ______.

A) generate the hydraulic pressure needed to apply the brake mechanisms
B) automatically pump the brakes during panic stops
C) supply mechanical force to the brake mechanisms
D) all answers are correct

Question 34

While discussing brake fluids, Technician A says hygroscopic brake fluid absorbs moisture from the air. Technician B says DOT 3 brake fluid has a higher boiling point than DOT 4 fluid. Who is correct?

A) A only
B) B only
C) both A and B
D) neither A nor B

Question 35

On a disc/drum system, the rear drum brakes lock up when the brake pedal is pressed hard. Technician A says the proportioning valve may not be functioning. Technician B says the axle height valve may be out of adjustment. Who is correct?

A) A only
B) B only
C) both A and B
D) neither A nor B

Question 36

The purpose of a pressure differential valve is being discussed. Technician A says it alerts the driver if pressure is lost in either portion of a dual braking system. Technician B says it provides the needed pressure balance between the front and rear brakes. Who is correct?

A) A only
B) B only
C) both A and B
D) neither A nor B

Question 37

Which of the following fluids should be used in brake systems?

A) power steering fluid
B) engine oil
C) transmission oil
D) none of these answers is correct

Question 38

The amount of pressure exerted by the brakes is being discussed. Technician A says short brake lines generate more pressure than long brake lines. Technician B says the condition of the piston seals in the master cylinder influences the amount of pressure developed. Who is correct?

A) A only
B) B only
C) both A and B
D) neither A nor B

Question 39

Which of the following is NOT a component of a typical dual master cylinder?

A) primary piston
B) piston stop bolt
C) pressure relief valve
D) secondary cup

Question 40

Technician A says power brakes are designed with vacuum-assisted units that use engine vacuum. Technician B says power brakes are designed with vacuum-assisted units that use vacuum developed by an external pump. Who is correct?

A) A only
B) B only
C) both A and B
D) neither A nor B

Question 41

A technician is diagnosing a car that had both front brake hoses replaced 5,000 miles ago. An inspection reveals that the right front brake hose has ruptured. Technician A says the specifications called for DOT 3 fluid; using DOT 4 fluid caused the failure. Technician B says the brake hose was twisted and stressed too much when installed. Who is correct?

A) A only
B) B only
C) both A and B
D) neither A nor B

Question 42

Which of the following is NOT used as a friction material in NAO brake pads?

A) nut shells
B) asbestos
C) powdered metals
D) graphite

Question 43

An aluminum master cylinder ______.

A) has a plastic fluid reservoir
B) has an anodized bore
C) is often called a composite master cylinder
D) all answers are correct

Question 44

As brake fluid absorbs moisture, _____.

A) it becomes acidic
B) it becomes alkaline
C) it oxidizes
D) its boiling point drops

Question 45

If the master cylinder has a large rear chamber and a smaller front chamber, _____.

A) the large chamber supplies fluid for the rear drum brake
B) the large chamber supplies fluid for the front disc brakes
C) the vehicle has a dual diagonal split brake system
D) the vehicle has four wheel disc brakes

Question 46

A technician is diagnosing a vehicle with a braking system problem. When she removes the filler cap to check the fluid level in the master cylinder, she notices that the rubber seal on the cap is swollen and has begun to disintegrate. What could be the problem?

A) water in the brake fluid
B) petroleum-based lubricants in the fluid
C) fluid overheating
D) incorrect type of brake fluid

Question 47

Brake lines are made of ______.

A) seamless copper tubing
B) extruded copper clad aluminum tubing
C) double-wall steel tubing
D) all answers are correct

Question 48

The residual pressure check valve is used in the hydraulic circuit for ______ brakes.

A) disc
B) drum
C) both "disc" and "drum"
D) neither "disc" nor "drum"

Question 49

Technician A says when the Brake warning light is illuminated, there is a difference in pressure between the two brake hydraulic circuits. Technician B says the Brake warning light is illuminated when the fluid level in the master cylinder reservoir is low. Who is correct?

A) A only
B) B only
C) both A and B
D) neither A nor B

Question 50

Organic friction material _____ semimetallic materials.

A) is quieter than
B) is more fade resistant than
C) requires higher pedal pressure than
D) is only used on front disc brakes rather than

Question 51

The brake light [stop light] switch is located _____ on modern vehicles.

A) on the master cylinder
B) on a bracket above the brake pedal
C) on the combination valve
D) all answers are correct

Question 52

A proportioning valve reduces fluid pressure to ______.

A) the front brakes during initial brake [low pedal force] application
B) the rear brakes during initial [low pedal force] brake application
C) the front brakes during hard braking
D) the rear brakes during hard braking

Question 53

Synthetic linings are made of _____

A) fiberglass
B) aramid fiber
C) both "fiberglass" and "aramid fiber"
D) neither "fiberglass" nor "aramid fiber"

Question 54

A vehicle waiting at a stop light with the brakes applied is held in place by _____ friction.

A) static
B) kinetic
C) both "static" and "kinetic"
D) neither "static" nor "kinetic"

Question 55

A master cylinder that has a bulge at the rear, near the mounting flange, is a _____type master cylinder.

A) self-compensating
B) auto compensating
C) dual stage
D) quick take-up

Question 56

A metering valve is found only on cars and trucks with ______.

A) four wheel disc brakes
B) four wheel drum brakes
C) disc front and drum rear brakes
D) dual diagonal brake circuits

Question 57

If a force of 150 pounds is applied to a master cylinder with a piston area of 1 square inch, how much force is developed on a wheel cylinder that has a piston area of 2 square inches?

A) 75 pounds
B) 150 pounds
C) 300 pounds
D) 450 pounds

Question 58

Technician A says low-drag calipers retract the pistons and pads farther from the rotor than traditional calipers. Technician B says systems that use low-drag calipers cannot use quick take-up master cylinders. Who is correct?

A) A only
B) B only
C) both A and B
D) neither A nor B

Question 59

Technician A says the size of the pads, shoes, drums, and rotors is based on the weight of the vehicle. Technician B says their size is base on the top speed of the vehicle. Who is correct?

A) A only
B) B only
C) both A and B
D) neither A nor B

Question 60

Semimetallic brake linings are being discussed. Technician A says they are more efficient than organic linings at low temperatures. Technician B says they are more fade resistant than organic materials but require higher brake pedal effort. Who is correct?

A) A only
B) B only
C) both A and B
D) neither A nor B

Question 61

Brake fluid is stored above the master cylinder in the ____________________.

Question 62

A technician is checking a car with an owner's complaint of poor braking performance and a low brake pedal. The master cylinder is full, and there are no signs of fluid leaks in the brake system. When he holds firm pressure on the brake pedal, the pedal slowly drops. What could be the problem?

A) internally leaking master cylinder
B) internally leaking caliper
C) leaking wheel cylinder
D) frozen pressure differential valve

Question 63

What color is clean brake fluid?

A) clear or amber
B) red
C) dark blue
D) brown

Question 64

The brake system converts the momentum of the vehicle into ____________________.

Question 65

____________________ bleeding is performed on a master cylinder before it is installed on the vehicle.

Question 66

The ____________________ is a housing that contains the disc brake piston, seal, and boots.

Question 67

In a drum brake assembly, the brake shoes are forced outward by pistons located inside the ____________________.

Question 68

A dual brake system uses a ____________________ master cylinder.

Question 69

After replacing a vacuum booster, the brakes lock up on a road test. Technician A says there is air trapped inside the brake lines. Technician B says the power booster pushrod needs adjustment. Who is correct?

A) A only
B) B only
C) both A and B
D) neither A nor B

Question 70

The function of the nitrogen-charged pneumatic accumulator on a hydraulic brake booster is to _____.

A) prevent power steering fluid from mixing with brake fluid
B) provide reserve power assist pressure if the engine stalls
C) reduce boost pressure when pedal effort is less than 10 psi
D) hold return pressure until the brake pedal is released

Question 71

The upward movement of the rear suspension opens the ______.

A) residual pressure check valve
B) metering valve
C) height-sensing proportioning valve
D) pressure differential valve

Question 72

Always keep master cylinder covers tightly sealed to prevent air, dirt, or ____________________ from contaminating the fluid.

Question 73

____________________ rotors consist of two machined braking surfaces separated by a finned center section for improved cooling.

Question 74

Before servicing a hydraulic power booster system, ______.

A) disconnect the battery
B) drain the power steering reservoir
C) pump the brake pedal with the engine off until the pedal goes hard
D) open all four brake bleeders

Question 75

Technician A bleeds the brakes system manually with the help of an assistant. Technician B uses a pressure bleeder. Who is correct?

A) A only
B) B only
C) both A and B
D) neither A nor B

Question 76

The actuator lever on the height-sensing proportioning valve is connected to the ____________________.

Question 77

What is the function of the line printed along the length of a brake hose?

A) It indicates that the hose has a neoprene liner
B) It ensures that the hose is orientated outward, toward the wheel
C) It indicates whether the hose is twisted
D) It indicates that the hose is mounted on the left side; right side hoses have no line

Question 78

The owner of a vehicle complains the car is hard to stop. The technician doing the diagnosis starts by pumping the brake pedal several times with the engine off, and then starts the engine while holding firm pressure on the brake pedal. The pedal falls away slightly and less pressure is needed to maintain the pedal in any position. This test proves that ______.

A) the master cylinder is working
B) the vacuum booster is working
C) the front brakes require adjustment
D) there is air in the hydraulic system

Question 79

____________________ sensors are built into the brake fluid reservoir body or cap.

Question 80

Bleeding a hydraulic system involves removing ____________________ from the system.