Automotive and Mechanics Brake Systems 3

Question 1

Which ABS component directly modulates hydraulic brake pressure to individual wheels during an ABS-activated stop?

Accepted Answer

Hydraulic control unit (HCU) / modulator assembly

Answer

Wheel speed sensor ring

Answer

ABS electronic control module

Answer

Vacuum brake booster

Question 2

Brake rotor lateral runout (side-to-side wobble) is measured using which instrument?

Accepted Answer

Dial indicator

Answer

Outside micrometer

Answer

Feeler gauge set

Answer

Hydraulic pressure gauge

Question 3

A brake caliper that seizes in the partially applied position will most likely cause which symptom?

Accepted Answer

Accelerated wear on one brake pad and excessive heat at that wheel corner

Answer

A soft, spongy brake pedal feel

Answer

Illumination of the ABS warning light

Answer

A pulsating brake pedal felt on all four wheels

Question 4

Electronic Stability Control (ESC) improves vehicle stability during cornering primarily by:

Accepted Answer

Selectively applying brakes to individual wheels to correct understeer or oversteer

Answer

Locking all four wheels simultaneously to prevent skidding

Answer

Increasing engine torque to the outside wheels during a turn

Answer

Automatically engaging the parking brake at speeds below 5 mph

Question 5

A rhythmic pulsation or vibration felt through the brake pedal during braking is most often caused by:

Accepted Answer

Excessive rotor lateral runout or disc thickness variation (DTV)

Answer

Low brake fluid level in the reservoir

Answer

A swollen or deteriorated flexible brake hose

Answer

A defective ABS wheel speed sensor

Question 6

Brake fluid is described as hygroscopic, which means it will:

Accepted Answer

Absorb water vapor from the atmosphere over time

Answer

Become more viscous as brake temperatures rise

Answer

Resist corrosion of master cylinder bore surfaces

Answer

Provide continuous lubrication for caliper piston seals

Question 7

The red brake warning light on the instrument panel typically illuminates due to which of the following conditions?

Accepted Answer

Low brake fluid level, an engaged parking brake, or a hydraulic circuit fault

Answer

Normal ABS activation during a hard stop

Answer

Brake pads that have just reached their maximum new thickness

Answer

Brake booster vacuum pressure exceeding the rated limit