freeasestudyguides Brakes 31-35

After replacing all four rotors and pads on a disc brake system, a pulsation is still felt in the steering wheel when braking. Which of the following is MOST likely causing this vibration?

• Sticking slide pins.

• Thickness variation.

• A rusty hub flange.

• Leaking Wheel cylinder

Answer explanation

A rusty hub flange can cause uneven rotor contact, leading to pulsation in the steering wheel when braking. This issue persists even after replacing rotors and pads, making it the most likely cause of the vibration.

A vehicle with a front disc rear drum brake system nosedives while lightly braking. Which of the following is causing this condition?

• The metering valve.

• Worn brake pads.

• The proportioning valve.

• Over-adjusted brakes.

Answer explanation

The metering valve regulates brake fluid to the front disc brakes, affecting weight transfer during braking. If it malfunctions, it can cause excessive nosedive, especially in a front disc/rear drum system.

A vehicle has a grinding noise that gets louder and changes pitch while turning right. Which of the following is causing this noise?

• A grabbing left front brake.

• A faulty left front wheel bearing.

• A cupped left front tire.

• Worn left front strut.

Answer explanation

The grinding noise that changes pitch while turning right indicates a faulty left front wheel bearing. This component can cause increased friction and noise, especially under load when turning.

A technician is replacing a brake hose and a damaged section of brake line tubing. Which of the following is correct?

• Repair damaged brake line with a compression fitting.

• Re-use the original brass washer when replacing a brake hose.

• Use double-wall steel tubing.

• Use single-wall copper tubing.

Answer explanation

Using double-wall steel tubing is correct as it provides better strength and durability for brake lines. Compression fittings and reusing brass washers can compromise safety, while single-wall copper tubing is not suitable for brake systems.

Which component is responsible for providing vacuum assistance to the brake system?

• Brake booster.

• Master cylinder.

• Brake rotor.

• Brake caliper.

Answer explanation

The brake booster is responsible for providing vacuum assistance to the brake system, enhancing braking power by amplifying the force applied to the brake pedal.

What is the effect of air bubbles in the brake lines?

• A hard brake pedal.

• Increased brake noise.

• A soft spongy pedal.

• Brake fluid leakage.

Answer explanation

Air bubbles in brake lines compress under pressure, leading to a soft spongy pedal. This reduces the effectiveness of braking, making it feel less responsive compared to a firm pedal with no air in the lines.

Which of the following materials is NOT suitable for brake line tubing?

• Single-wall copper.

• Stainless steel.

• Double-wall steel.

• Alloy-coated steel.

Answer explanation

Single-wall copper is not suitable for brake line tubing because it can corrode and is less durable under high pressure compared to stainless steel, double-wall steel, and alloy-coated steel, which are all more reliable options.

What is the consequence of using a compression fitting on a brake line?

• Reduced brake noise.

• Improved brake fluid flow.

• Increased brake efficiency.

• Inability to withstand high pressure.

Answer explanation

Using a compression fitting on a brake line can lead to an inability to withstand high pressure, compromising brake performance and safety. This is critical as brake lines must handle significant pressure during operation.