Question 1

In the unapplied position, drum brake shoes are held against the anchor pin by the ______.

Accepted Answer

Return springs pull the brake shoes back to their resting position against the anchor pin when the brakes are not applied.

Question 2

On most vehicles, the automatic adjuster system ______.

Accepted Answer

The automatic adjuster system is typically installed on the secondary shoe of drum brakes.

Question 3

A buildup of brake dust and dirt between the lining and the drum is the most common cause of a ______.

Accepted Answer

A buildup of brake dust and dirt between the lining and the drum can cause abrasion and scoring on the drum surface, leading to a scored drum surface.

Question 4

In a typical drum brake, which component provides a foundation for the brake shoes and associated hardware?

Accepted Answer

The backing plate serves as the foundation for the brake shoes and associated hardware in a drum brake system, providing a solid base for the components to function against.

Question 5

Technician A tests brake drums for out-of-round using a dial indicator. Technician B measures the drum diameter in several places to check for out-of-round. Who is correct?

Accepted Answer

The answer of Technician A tests brake drums for out-of-round...

Question 6

Technician A says the discard dimension of a brake drum is the drum's allowable machining dimension. Technician B says a drum may be machined and used if within 10 percent of the discard dimension. Who is correct?

Accepted Answer

The discard dimension of a brake drum is the maximum allowable diameter to which the drum can be safely machined or worn before it must be replaced, not the allowable machining dimension. A drum should not be used if it is at or beyond this discard dimension, not within 10 percent of it.

Question 7

The function of the wheel cylinder is to ______.

Accepted Answer

The wheel cylinder converts hydraulic pressure from the brake fluid into mechanical force, which is then applied to the brake shoes, causing them to press against the drum and slow the vehicle.

Question 8

Technician A says brake linings are riveted to the brake shoes. Technician B says brake linings are bonded to the brake shoes. Who is correct?

Accepted Answer

Brake linings can be either riveted or bonded to the brake shoes, meaning both Technician A and Technician B are correct.

Question 9

After resurfacing a brake drum, Technician A cleans it using hot soapy water and a lint-free cloth until it is thoroughly dry. Technician B cleans the drum using a lint-free cloth dipped in a special brake cleaning solution. Who is correct

Accepted Answer

The answer of After resurfacing a brake drum, Technician A...

Question 10

Brake linings should be replaced when linings are ______.

Accepted Answer

Brake linings should be replaced when they are worn to within 1/32 inch (.794 mm) of a rivet head, contaminated with oil or grease, or contaminated with brake fluid. All these conditions compromise the braking system's effectiveness and safety.

Question 11

Technician A says an out-of-round drum can cause a pulsating brake pedal. Technician B says an out-of-round drum can cause the brakes to grab. Who is correct?

Accepted Answer

Both technicians are correct. An out-of-round drum can cause a pulsating brake pedal due to uneven contact with the brake shoes, and it can also cause the brakes to grab as the high spots on the drum make contact with the brake shoes.

Question 12

Technician A says some drums are made entirely of cast iron. Technician B says some drums are made entirely of aluminum. Who is correct?

Accepted Answer

The answer of Technician A says some drums are made...

Question 13

Rear wheel brake drum removal is being discussed. Technician A says that on some FWD vehicles, the rear bearings must be disassembled to remove the drum. Technician B says that on some FWD vehicles, the drums are held in place by wheel lugs. Who is correct?

Accepted Answer

Both statements are correct. On some front-wheel-drive (FWD) vehicles, the rear wheel bearings must be disassembled to remove the brake drum, and on others, the drums are indeed held in place by the wheel lugs.

Question 14

Servicing a brake drum with hard spots that are causing chatter and brake pull is being discussed. Technician A says he can grind off the hard spots. Technician B says the drum must be replaced. Who is correct?

Accepted Answer

Technician B is correct because grinding off hard spots on a brake drum can compromise the structural integrity of the drum, making it unsafe. The proper solution for a brake drum with hard spots causing chatter and brake pull is replacement.

Question 15

Duo-servo drum brakes are also known as __________.

Accepted Answer

Duo-servo drum brakes are known as self-energizing brakes because the rotation of the drum can pull the shoes into tighter contact with the drum, enhancing the braking force without additional pedal force.

Question 16

Technician A says on most vehicles, the self-adjuster system is installed on the primary shoe. Technician B says the system will self-adjust when the brakes are applied and the vehicle is backing up. Who is correct?

Accepted Answer

Technician B is correct. The self-adjuster system typically adjusts when the brakes are applied while the vehicle is moving in reverse. Technician A is incorrect because the self-adjuster is usually installed on the secondary shoe, not the primary shoe.

Question 17

Technician A says brake shoe return springs can be separately hooked into a link or a guide. Technician B says the springs may be strung between the shoes. Who is correct?

Accepted Answer

Brake shoe return springs can indeed be hooked into a link or a guide (Technician A's statement) and can also be strung between the shoes (Technician B's statement), making both technicians correct. These configurations help in retracting the brake shoes away from the drum after the brake pedal is released, ensuring the system works efficiently.

Question 18

A drum with a taper or out-of-roundness exceeding 0.006 inch (0.152 mm)is considered ______.

Accepted Answer

A drum with a taper or out-of-roundness exceeding 0.006 inch (0.152 mm) is considered unacceptable because it can lead to improper brake functioning. It must be turned or replaced to ensure the vehicle's braking system operates safely and effectively.

Question 19

The parking brake cables should be adjusted before performing regular wheel brake service.

Accepted Answer

The parking brake cables should be adjusted after performing regular wheel brake service to ensure the brakes are properly serviced and functioning before any adjustments to the parking brake system are made.

Question 20

Duo-servo drum brake systems are being discussed. Technician A says the primary shoe lining is often thicker than the secondary shoe lining. Technician B says the primary shoe typically has more lining surface area than the secondary shoe. Who is correct?

Accepted Answer

In duo-servo drum brake systems, the primary shoe lining is typically thinner and has less surface area than the secondary shoe lining. The secondary shoe does more of the braking work, so it is designed to have more lining material.

Quiz 51: Drum Brakes