freeasestudyguides Brakes 26-30

What should be avoided when a ridge has formed on the backing plate's pads where the brake shoes rest?

• Apply bearing grease to reduce brake squeak.

• File the pads to restore a smooth finish.

• Sand the pads to restore a smooth finish.

• Apply a lubricant for high-temperature brake systems.

Answer explanation

Applying bearing grease can lead to brake failure and reduced performance. It is crucial to avoid this to ensure safe braking. Instead, focus on restoring the pads' surface through filing or sanding.

If the brake pedal is low and feels soft, which of the following could be the cause?

• Worn front brake pads.

• A leaking vacuum brake booster.

• Air bubbles in the brake fluid.

• Over-adjusted rear brake shoes.

Answer explanation

Air bubbles in the brake fluid can compress under pressure, causing a soft brake pedal feel. This is a common issue that affects braking performance, unlike worn pads or booster leaks.

What is the function of a height sensing proportioning valve?

• Is adjusted with all four tires raised in the air.

• Delays pressure to the front brakes.

• Prevents rear wheel lockup.

• Prevents nosedive while braking.

Answer explanation

The height sensing proportioning valve is designed to prevent rear wheel lockup during braking by adjusting brake pressure based on the vehicle's load, ensuring stability and control.

What could cause a fault code for the left rear wheel speed sensor in a light truck with four-wheel ABS?

• broken Wheel stud

• Mud and road debris caught between the tone sprocket and the sensor.

• Check the wheel bearing for looseness and wear.

• Left Rear Strut

Answer explanation

A fault code for the left rear wheel speed sensor can be caused by mud and debris obstructing the sensor or tone sprocket, and by checking the wheel bearing for looseness and wear, which can affect sensor performance.

What is the effect of over-adjusted rear brake shoes?

• A hard brake pedal.

• Increased stopping distance.

• A low spongy brake pedal.

• Overheating and brake drag.

Answer explanation

Over-adjusted rear brake shoes can lead to overheating and brake drag because they create excessive friction against the drum, causing the brakes to not fully release. This results in increased heat and potential brake performance issues.

What is the result of worn front brake pads?

• Noise from the chatter clips.

• A low spongy brake pedal.

• A hard brake pedal.

• Increased stopping distance.

Answer explanation

Worn front brake pads can cause noise from the chatter clips, which are designed to alert the driver of pad wear. This is a common symptom, while other options like a spongy pedal or increased stopping distance are not directly caused by worn pads.

What is the consequence of a leaking vacuum brake booster?

• A low spongy brake pedal.

• A hard brake pedal.

• Overheating and brake drag.

• A warning lamp from the electronic brake pad wear indicator.

Answer explanation

A leaking vacuum brake booster reduces the assist provided to the brake pedal, resulting in a hard brake pedal feel. This occurs because the vacuum pressure needed for proper braking is compromised.