Deck 8: Drum Brakes

Question 1

Technician A says duo-serve brakes only self-adjust in reverse. Technician B says only leading-trailing brakes will self-adjust as necessary going in either direction. Who is correct?

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

Answer 1

C

Question 2

Rear-wheel drive braking systems are being discussed. Technician A says this type of vehicle has separate drums and hubs on the front axle. Technician B says rear drums mount on a flange attached to the axle on RWD vehicles. Who is correct?

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

Answer 2

B

Question 3

All of the following statements about brake drum measuring and condition are true EXCEPT:

A)if the highest and lowest measurements taken at any straight-line position across the drum vary by 0.006 inch or more, machine the drum to correct the problem.
B)the diameter measured at the deepest groove must be 0.030 inch (0.75 mm)or more under the discard dimension .
C)drums that are smooth and true but exceed the new diameter by 0.090 inch or more should be reused without turning.
D)even slightly rough drum surfaces should be turned to ensure a true drum surface.

Answer 3

C

Question 4

Which of the following will cause pulsation in the brake pedal when the brakes are applied?

A)Loose lining
B)Grease on linings
C)Out-of-round drum
D)All of the above

Question 5

Technician A says leading-trailing brakes are also called full-servo brakes. Technician B says duo-servo brakes are also called non-servo brakes. Who is correct?

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

Question 6

On a duo-servo brake adjuster, what actually engages the starwheel to cause it to turn?

A)A lever or pawl
B)The cable itself
C)The primary shoe
D)The secondary shoe

Question 7

Technician A says leading-trailing shoe drum brakes may have cam-type adjusters. Technician B says leading-trailing shoe drum brakes may have starwheel adjusters. Who is correct?

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

Question 8

Technician A says an inspection of the braking system should include the wheel assemblies. Technician B says a brake inspection includes components of the steering and suspension systems. Who is correct?

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

Question 9

Which of the following will most likely cause the vehicle to pull to one side?

A)An improperly adjusted front shoe
B)A loose backing plate
C)A scored drum
D)All of the above

Question 10

Technician A says the primary shoe is usually the shoe toward the front of the vehicle. Technician B says the lining material on the secondary shoe usually has less area than that on the primary shoe. Who is correct?

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

Question 11

Brake linings are:

A)primarily made of semi-metallic materials.
B)primarily made of synthetic materials that have replaced asbestos.
C)attached to the shoes by either bonding or riveting.
D)All of the above.

Question 12

Technician A says the wheel cylinder has pressurized brake fluid applied to the pistons inside the cylinder. Technician B says the pistons act on the brake shoes to move them into contact with the brake drum. Who is correct?

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

Question 13

What provides the friction surfaces necessary for stopping the wheel?

A)Wheel cylinder
B)Springs
C)Drum and shoes
D)All of the above

Question 14

Technician A says the following illustration shows the mechanism for a leading-trailing brake self-adjuster. Technician B says the following illustration shows a duo-servo brake assembly. Who is correct?

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

Question 15

Technician A says glazed or worn linings are the most common cause of drum brake problems. Technician B says such problems include hard pedal, pulling to one side, wheel locking, brake chatter, excessive pedal travel, noisy brakes, grabbing brakes, or little or no braking power . Who is correct?

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

Question 16

Grabbing rear drum brakes are often caused by:

A)glazed linings.
B)grease on linings.
C)contaminated linings.
D)out-of-round drum.

Question 17

Technician A says it is okay to replace both front brakes without replacing the rear brakes. Technician B says it is okay to replace the brakes on one side of an axle without replacing the other side. Who is correct?

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

Question 18

Technician A says the setup shown in the following figure is being used to check drum internal diameter. Technician B says the setup shown in the following figure is being used to check for an out-of-round drum. Who is correct?

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

Question 19

Technician A says a lthough four-wheel disc brakes have become standard equipment of most cars and light trucks, drum brakes continue to be in use for a few rear-wheel brakes . Technician B says no law or regulation requires disc brakes, but the brake performance requirements of FMVSS 105 make front disc brakes virtually mandatory . Who is correct?

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

Question 20

Technician A says d rum brake disadvantages include poorer heat dissipation and less fade resistance than disc brakes . Technician B says d rum brake disadvantages include lack of  self-adjustment without special linkage, and a greater tendency than disc brakes to pull and grab.  Who is correct?

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

Question 21

Name the basic parts of a drum brake.

Question 22

How is the ratchet-type self- adjuster for leading-trailing brakes operated?

Question 23

Technician A says the frictional energy on the drum surface creates heat, and this heat is dissipated to the surrounding air as the drum rotates with the wheel. Technician B says the thinner a drum gets, the better its ability to absorb and release heat. Who is correct?

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

Question 24

The drum measurement shown below is being discussed. The drum has a discard diameter of 11.400 inch. Technician A says to replace the drum. Technician B says the drum can be turned 0.005 inch and reused. Who is correct?

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

Question 25

Technician A says new drums may be protected by a coating that must be thoroughly cleaned off the friction surfaces before installing the drums. Technician B says refinished drums contain metal particles that must be removed before installing the drums. Who is correct?

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

Question 26

If a star adjuster is installed on the wrong side of the vehicle, what will happen?

Question 27

Technician A says both drums on an axle should be machined to the same diameter. Technician B says drum diameters must be within 0.005 inch of one another. Who is correct?

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

Question 28

What causes drum threading?

A)Excessive heat
B)Worn shoes or springs
C)Improper brake lathe use
D)Tight shoe adjustment

Question 29

Explain how self-energizing brake shoes work on a primary-secondary system.

Question 30

The starwheel adjusting screw threads should be lubricated with:

A)brake lubricant.
B)brake fluid.
C)penetrating oil.
D)any of the above.

Question 31

Name four common causes of drum scoring.

Question 32

Technician A says the scratch cut shown below indicates that the drum is mounted on the lathe correctly. Technician B says the silencer band shown in the following figure is used to produce a smoother drum finish. Who is correct?

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

Question 33

Name the two methods of attaching linings to brake shoes.

Question 34

Technician A says that in a self-energizing brake, the rotation of the drum decreases the braking force of the lining against the drum. Technician B says that the force of the brake drum is added to the force supplied by the wheel cylinder. Who is correct?

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

Question 35

The backing plate shoe support pads should be:

A)cleaned and lubricated with brake lubricant.
B)cleaned with a file/grinder and left to dry.
C)cleaned with a cleaner and left to dry.
D)any of the above.

Question 36

What action is shown in the following illustration?
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Question 37

Technician A says the wheel cylinder springs are return springs. Technician B says the shoe return springs push the pistons back in place. Who is correct?

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

Question 38

If the brake drum will not come off the hub, what should be done?

Question 39

Define a servo brake system.

Question 40

Technician A says brake drums with moderate to severe scoring can be refinished by either turning on grinding on a brake lathe. Technician B says brake drums with moderate to severe scoring must be replaced. Who is correct?

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

Question 41

The drum surface becomes hot because of ____________________ developed by the braking action.

Question 42

How is a cracked drum serviced?

Question 43

____________________ drums mount on a flange attached to the axle on RWD vehicles.

Question 44

The backing plate provides the mounting platform for the brake assembly and closes the rear of the mounted brake drum.

Question 45

Drum rotation adds ____________ to the brake shoes as they contact the drums. This is called self-energizing action.

Question 46

The primary brake shoe is sometimes called the trailing shoe.

Question 47

Drum brakes provide a better _____________ coefficient than do disc brakes.

Question 48

The coefficient of friction for the primary lining is often higher than for the secondary lining to provide good stopping power .

Question 49

Every service drum brake assembly has two brake shoes.

Question 50

Brake shoes are held against their anchors and adjusters by springs.

Question 51

The larger the vehicle, the larger the brake drum.

Question 52

The leading shoe is ____________, but the trailing shoe is _______________ in a leading-trailing brake.

Question 53

Some brake drums are finned to help them dissipate heat more efficiently.

Question 54

The brake shoe ____________________ is the metal part of the brake shoes to which linings are attached.

Question 55

The duo-servo brake is also called a self-energizing brake.

Question 56

When the brakes operate, the wheel cylinder forces one end of the leading shoe ____________________ against the drum.

Question 57

On some leading trailing shoe brake systems the shoes can be reversed because doing so will not affect braking.

Question 58

The wheel cylinder and brake shoes are mounted on a solid backing plate, which is attached to the axle housing or ____________________.

Question 59

___________ occurs when water is trapped between the brake linings and the drum or rotor and reduces the coefficient of friction.

Question 60

One-piece cast-iron drums are often seen on late-model vehicles.

Question 61

_____________ is a condition that occurs under hard braking when hot gases and dust particles are trapped between the brake linings and the drum or rotor and build up pressure that acts against brake force .