freeasestudyguides 51-55

A vehicle with a Hydroboost brake system has reduced braking performance. Which of these could be the cause?

• A faulty power steering pump.

• A faulty vacuum check valve.

• Low manifold vacuum.

• A clogged inlet valve.

Answer explanation

A faulty power steering pump can lead to insufficient hydraulic pressure in a Hydroboost system, resulting in reduced braking performance. The other options are less likely to directly affect the Hydroboost operation.

A vehicle with four-wheel disc brakes, ABS, and a vacuum brake booster has a hard brake pedal and an increased stopping distance. Which of the following is causing this condition?

• Worn brake pads.

• A faulty brake booster.

• Air in the brake lines.

• Bypassing master cylinder cup seals.

Answer explanation

A faulty brake booster can cause a hard brake pedal and increased stopping distance by failing to provide the necessary vacuum assist, making it difficult to apply sufficient braking force.

A vehicle drifts to the right while driving forward. Which of these could be the cause?

• Leaking master cylinder cup seals.

• Sticking right front caliper slide pins.

• A restriction in the left front brake line.

• A seized left front caliper.

Answer explanation

The vehicle drifts to the right likely due to sticking right front caliper slide pins, which can cause uneven braking. This results in the vehicle pulling to one side while driving forward.

The brake shoes on a self-energizing drum brake system require replacement. All of the following statements are correct about replacing these brake shoes EXCEPT:

• The secondary shoe faces the rear of the vehicle.

• The secondary shoe has a shorter brake shoe lining.

• Shoe lining can be riveted or glued to the shoe.

• The primary shoe faces the front of the vehicle.

Answer explanation

The statement "The secondary shoe has a shorter brake shoe lining" is incorrect. In a self-energizing drum brake system, the secondary shoe typically has a longer lining to enhance braking efficiency.

What is a symptom of a faulty or leaking brake booster?

• A squeal when braking.

• A low brake pedal that fades to the floor.

• A hard brake pedal and increased stopping distance.

• A soft spongy brake pedal.

Answer explanation

A hard brake pedal and increased stopping distance indicate a faulty brake booster, as it reduces the power assist needed for effective braking, making it harder to stop the vehicle.

What happens if the primary and secondary brake shoes are reversed in a self-energizing drum brake system?

• The vehicle will have a soft brake pedal.

• The vehicle will pull to one side while driving forward.

• The brake pedal will be hard.

• The brakes will make a squealing noise.

Answer explanation

Reversing the primary and secondary brake shoes in a self-energizing drum brake system disrupts the braking force distribution, causing uneven braking. This can lead to the vehicle pulling to one side while driving forward.

What is the function of a quick take-up master cylinder?

• To reduce the wear on brake pads.

• To improve the vehicle's fuel efficiency.

• To provide more brake fluid volume to add space between the pads and the rotor.

• To increase the pressure in the brake lines.

Answer explanation

The quick take-up master cylinder increases brake fluid volume, allowing for quicker engagement of the brake pads with the rotor, which enhances braking efficiency and responsiveness.