Chapter 7

Question 1

Front calipers are mounted on _______________ _______________ or adapters that may be an inte- gral part of the steering knuckles.

Answer 1

Caliper Supports

Question 2

When any brake installation reaches its limit of heat dissipation, _______________ _______________ sets in.

Answer 2

Brake Fade

Question 3

3. _______________ rotors are made of different materials, usually cast iron and steel, to reduce weight.

Answer 3

Composite

Question 4

. _______________ linings usually wear faster than do semi-metallic linings, but they have the benefit of breaking in faster.

Answer 4

Organic

Question 5

With disc brakes most of the _______________ area is cooling while only a small area
directly contacts the friction materials at any given time.

Answer 5

Swept Area

Question 6

Disc brakes do not suffer from _______________ fade because the rotor does not expand away from the pads.

Answer 6

Mechanical

Question 7

Low-drag calipers require a quick take-up _______________ cylinder.

Answer 7

Master

Question 8

The _______________ _______________ _______________ converts hydraulic
pressure from the master cylinder to mechanical force.

Answer 8

Disk Brake Caliper

Question 9

Many rear disc brakes have a small brake drum built into the center of the _______________.

Answer 9

Rotor

Question 10

Sliding or floating calipers have a piston only on the_______________ side.

Answer 10

Inboard

Question 11

The advantages and disadvantages of disc brake systems are being discussed. Technician A says that disc brakes are more likely to develop brake fade and water fade. Technician B says that reduc- tion of mechanical fade and gas fade is an advan- tage of disc brakes. Who is correct?

Answer 11

Both A and B

Question 12

The operation of disc brake systems is being dis- cussed. Technician A says that composite rotors were developed to save weight. Technician B says that a fixed rotor assembly is part of the hub. Who is correct?

Answer 12

Both

Question 13

Disc brake calipers are being discussed. Technician A says that a single caliper may have one, two, or more pistons. Technician B says that the piston seal is known as a square-cut seal. Who is correct?

Answer 13

Both

Question 14

Technician A says that solid rotors can usually be machined several times before their minimum thickness limits are reached. Technician B says that composite rotors have cast-iron hubs with steel friction surfaces. Who is correct?

Answer 14

Neither

Question 15

When discussing disc brake work, Technician A says that organic linings are a composite material made from bonding nonmetallic fibers. Technician B says that semi-metallic linings require higher brake pedal effort but are more fade resistant compared to organic linings. Who is correct?

Answer 15

Both

Question 16

Two technicians are discussing a disc brake caliper: Technician A says that calipers use springs to retract the seals after a brake application. Technician B says that sliding calipers typically use one piston on each side of the rotor. Who is correct?

Answer 16

Both

Question 17

Technician A says that a return spring is used to retract a caliper piston. Technician B says that the piston seal retracts the caliper piston when hydraulic pressure is released. Who is correct?

Answer 17

A Only

Question 18

Technician A says that inner and outer pad fric- tion materials may have different coefficients of friction. Technician B says to follow the manufac- turer’s recommendation for inboard and outboard pad linings when replacing brake pads. Who is correct?

Answer 18

Both

Question 19

Technician A says that when the driver hears the audible brake pad wear indicator, he or she should immediately park the car and not use it until the brakes are replaced. Technician B says that the wear pad indicators alert the driver to worn pads that should be replaced soon. Who is correct?

Answer 19

B only

Question 20

Technician A says that synthetic brake linings are nonorganic, nonmetallic, and non-asbestos mate- rials. Technician B says that synthetic brake lin- ings are made of aramid or fiberglass. Who is correct?

Answer 20

Both

Question 21

1. List the basic parts of a disc brake.

Answer 21

Rotor (hub and breaking surface) brake pads, Calipers

Question 22

2. Explain the advantages and disadvantages of an aluminum caliper.

Answer 22

Lightwaight for high performance, but very poor thermal insulator and increases the danger of boiling the brake fluid

Question 23

3. Why do manufacturers use two-piece rotors on some vehicles?

Answer 23

Reduces weight using different materialys, usually cast iron and steel. Friction surfaces are cast iron but supporting parts are steel to reduce weight

Question 24

4. In addition to keeping road splash off the brake assembly, why are splash shields used on disc
   brakes?

Answer 24

Important for directing air over the rotor to aid in cooling

Question 25

5. Why is asbestos no longer used for brake pad and shoe linings?

Answer 25

Caused severe health hazards

Question 26

What are common classifications of brake pad and shoe friction materials?

Answer 26

Organic, semi metallic, metallic, synthetic and ceramic

Question 27

6. What is the difference between fixed and sliding calipers?

Answer 27

Fixed caliper is bolted to its support and does not move when the brakes are applied. A fixed caliper must have pistons on both the inboard and outboard sides. Sliding caliper is mounted ontwo locating bolts or guide pins that are threaded into the caliper supper, the caliper slides on the pin in a sleeve or bushing

Question 28

How does a low-drag caliper operate?

Answer 28

Increase the clearance between the brake pads and rotors when the brakes are released. Recuing friction and improves fuel mileage. Requires a quick take up master cylinder to provide more fluid volume to the intial pedal movement to take up the greater pad to rotor clearance

Question 29

Explain how a floating caliper applies the brake pads.

Answer 29

Pressure behind the piston pushes the piston outward in its bore. The pressure is transmitted directly to the inboard pad which is forced against the inboard rotor surface. The pressure applied to the bottom of the cylinder bore forces the caliper to slide or move on the guide bins towards the inboard side. This movement causes the outboard section of the caliper to apply equal pressure against the back of the outoard pad forcing it against the outboard rotor surface

Question 30

7. Explain the purpose of a drum-in-hat rotor.

Answer 30

Small brake drum that acts as the parking brake in the center of the rotor. Two brake shoes are expanded into the brake drum when the parking brake is applied