Drum brake theory

Open Ended

How do hydraulic wheel cylinders contribute to the operation of drum brakes?

Multiple Choice

What is the primary function of the friction lining in drum brakes?

• To convert vehicle’s kinetic energy into heat energy

• To transfer heat directly to the atmosphere

• To reduce the weight of the brake system

• To lubricate the brake drum

Multiple Select

Which of the following can result from heavy brake use on drum brakes?

• Overheating of lining

• Brake fade

• Improved braking performance

• Overheating of brake fluid

Fill in the Blank

Drum brakes are generally less expensive to ___ than disc brakes.

Open Ended

Explain why repairing drum brakes can be more complicated than repairing disc brakes.

Multiple Choice

On which vehicles are drum brakes still commonly used?

• Front wheels of modern vehicles

• Rear wheels of vehicles with disc/drum brakes

• All four wheels of sports cars

• Only motorcycles

Multiple Choice

What is the main material used to manufacture brake drums in drum brake systems?

• Aluminum

• Steel

• Cast iron

• Copper

Multiple Choice

Which component of the drum brake system is made from stamped steel and supports wheel cylinders, brake shoes, and hardware?

• Backing plate

• Brake shoe

• Wheel cylinder

• Return spring

Open Ended

Explain how the wheel cylinder and brake shoe work together to stop a vehicle in a drum brake system.

Multiple Select

Which of the following are functions of springs and clips in a drum brake system?

• Retract brake shoes when brakes are released

• Hold brake shoes against backing plate

• Work with self-adjuster and parking brake linkage operation

• Convert brake pedal force into hydraulic pressure

Fill in the Blank

Automatic brake self-adjusters operate in one of two ways: either when using the brakes while backing up or as part of applying the ___.

Multiple Choice

When the brake pedal is depressed, which component converts brake pedal force into hydraulic pressure?

• Master cylinder

• Wheel cylinder

• Backing plate

• Parking brake mechanism

Multiple Choice

Which of the following best describes what happens when the brake pedal is depressed in a drum brake system?

• Pistons within each wheel cylinder are forced outward by hydraulic pressure, applying force to both brake shoes and forcing them into each rotating drum.

• Brake shoes are pulled inward by hydraulic pressure, causing the drum to rotate faster.

• The brake drum expands outward to contact the brake shoes, slowing the wheel.

• The brake shoes rotate freely with the drum, generating friction.

Multiple Select

Which of the following statements about drum brake shoes is/are correct?

• Each drum brake unit has two brake shoes.

• Shoes can be expanded mechanically or hydraulically.

• Shoes expand against the inside surface of the brake drum to slow the wheel.

• Brake shoes are always expanded by hydraulic pressure only.

Open Ended

Explain why drum brake systems must be adjusted to allow for lining wear and what could happen if they are not adjusted.

Fill in the Blank

The positioning of brake shoes determines whether the brake is ___ or not.

Open Ended

Describe the wedging effect in drum brakes and how it assists the driver in applying the brakes.

Fill in the Blank

Drum brakes are considered ___ because they can increase the applied force through friction and wedging effects.

Multiple Choice

Which of the following statements best describes the difference between leading shoes and trailing shoes in drum brakes?

• Leading shoes are self-energizing and installed in the same direction as drum rotation, while trailing shoes are not self-energizing and installed in the opposite direction.

• Leading shoes are installed in the opposite direction of drum rotation, while trailing shoes are self-energizing.

• Both leading and trailing shoes are self-energizing and installed in the same direction as drum rotation.

• Trailing shoes are more efficient than leading shoes and are always self-energizing.

Open Ended

Explain how servo action enhances the performance of drum brakes.

Multiple Select

Which of the following are main types of drum brake systems?

• Twin leading shoe

• Leading/trailing shoe (single leading)

• Duo-servo

• Disc brake

Fill in the Blank

The duo-servo drum brake uses servo action in both ___ .

Multiple Choice

Why was the twin leading shoe drum brake system once popular on front wheels?

• It was very efficient at braking in the forward direction, matching the needs of vehicles that travel faster forward than in reverse.

• It was the least expensive option for manufacturers.

• It provided equal braking efficiency in both forward and reverse directions.

• It required less maintenance than other types.

Open Ended

Describe the function and placement of the single-piston wheel cylinders in a twin leading shoe drum brake system.

Open Ended

After learning about drum brake fundamentals, what aspect of drum brake systems would you like to explore further or clarify?

Multiple Choice

What is the primary function of hydraulic wheel cylinders in a drum brake system?

• To rotate the brake drum

• To force brake shoes against the inside of the drum

• To secure the drum to the axle flange

• To lubricate the brake components