Deck 57: Brake Fundamentals

Question 1

While having a discussion, Technician A says that federal requirements call for the parking brake to stop a vehicle in motion. Technician B says that federal requirements simply call for the parking brake to "hold a parked vehicle," not stop a vehicle in motion. Who is correct?

A)A only
B)B only
C)Both A and B
D)Neither A nor B

Answer 1

B

Question 2

The ratio of the force holding two surfaces in contact to the force required to slide one over the other is known as the ____________________.

Answer 2

coefficient of friction

Question 3

While having a discussion, Technician A says that the braking system on a hybrid vehicle has the same parts as a conventional braking system. Technician B says that the system has regenerative braking, and computer controls operate the hydraulic brake system. Who is correct?

A)A only
B)B only
C)Both A and B
D)Neither A nor B

Answer 3

C

Question 4

As brake linings wear, clearance between the friction surfaces becomes smaller.

Question 5

The part that is MOST-Likely used to prevent the front brakes from applying until the rear drum brake shoes overcome return spring pressure and contact the brake drums is the:

A)metering valve
B)master cylinder
C)piston
D)proportioning valve

Question 6

During stopping, a drum brake's leading shoe digs into the brake drum. This action is called ____________________.

Question 7

Brake fluid that meets DOT 3 or DOT 4 specifications can be used in drum and disc systems.

Question 8

All of the following statements about the hydraulic braking system are true EXCEPT:

A)the force applied to the brake linings when the master cylinder operates is increased with a larger diameter wheel cylinder.
B)when larger wheel cylinders are used, the distance that the pedal has to travel before building up pressure increases.
C)in order to increase the pressure coming from the master cylinder, the diameter of its bore must be larger.
D)laws of hydraulic pressure can be applied to electrical fundamentals.

Question 9

____________________ states "pressure in an enclosed system is equal and undiminished in all directions."

Question 10

The friction materials used in cars and trucks are called ____.

A)riveted linings
B)brake linings
C)metallic linings
D)ceramic linings

Question 11

____ rear proportioning modulates rear brake pressures based on the speed of the wheels at the front and rear axles in newer ABS. .

A)Kinetic
B)Dynamic
C)Vacuum
D)Hydraulic

Question 12

The condition that MOST-Likely results from excessive brake heat is:

A)force
B)residual pressure
C)brake fade
D)friction

Question 13

When a car is traveling at freeway speed, a large amount of ____________________ energy is stored.

Question 14

All of the following statements are true EXCEPT:

A)disc brake systems always have a check valve.
B)a residual check valve would be a problem in split diagonal hybrid systems.
C)most master cylinders produced today are aluminum, with a plastic reservoir sealed to the cylinder with rubber grommets.
D)plastic reservoirs are transparent to allow the fluid level to be observed without removing the reservoir cover.

Question 15

Pressurizing a liquid to transfer motion or multiply and apply force is called ____________________.

Question 16

Remember Pascal's law: Pressure is equal everywhere in an enclosed system.

Question 17

Brake fluid can absorb a large enough quantity of water to be ruined in as little as one hour if left uncovered.

Question 18

Which of the following statements is LEAST-Likely true?

A)Brake lines are usually made of double-walled steel tubing coated with a rust-preventative material.
B)When a driver depresses the brake pedal, the linkage applies force to the piston at the rear of the master cylinder.
C)A master cylinder has four ports for each piston.
D)A secondary seal prevents fluid from leaking from the back of the master cylinder bore.

Question 19

Which of the following statements is LEAST-Likely true?

A)By design, disc brakes automatically adjust themselves, but drum brakes require periodic adjustment.
B)As drum brake linings wear, increased clearance between the lining and the drum results in more brake pedal travel before pressure can build and the brakes start to apply.
C)The disc brakes in the front and the drum brakes in the rear are connected hydraulically in the master cylinder.
D)The tandem master cylinder design prevents the rear brakes from applying fully before the front brakes contact the brake drum.

Question 20

Ceramic linings are organic linings with sponge iron and steel fibers mixed into them to add strength and temperature resistance.

Question 21

Briefly describe the four ingredients that are considered essential to all brake fluids.

Question 22

Briefly discuss the three main types of parking brakes.

Question 23

Why is it considered an advantage for brake fluid to be hygroscopic?

Question 24

What are the two purposes of preventing the front brakes from applying until the rear brakes start to build pressure?

Question 25

What is the purpose of the residual check valve at the fluid outlet on older master cylinders?