NAPA - National Automotive Parts Association Certified Mechanic Brake System Service Questions and Answers

Question 1

A customer complains of a pulsating brake pedal when stopping. Which of the following is the MOST likely cause?

Accepted Answer

Excessive rotor runout or thickness variation

Answer

Air in the hydraulic lines

Answer

Worn or unevenly worn brake pads

Answer

Seized caliper piston

Question 2

A technician is performing a brake fluid flush. What is the primary reason for periodically replacing brake fluid?

Accepted Answer

The fluid is hygroscopic and absorbs moisture, lowering its boiling point.

Answer

The fluid loses its viscosity over time.

Answer

The fluid becomes contaminated with metal particles.

Answer

The fluid's lubrication properties degrade, causing caliper wear.

Question 3

When bleeding the brakes on most non-ABS passenger vehicles, what is the generally accepted sequence?

Accepted Answer

Start with the wheel furthest from the master cylinder and work to the closest.

Answer

Start with the wheel closest to the master cylinder and work to the furthest.

Answer

Bleed the front wheels first, then the rear wheels.

Answer

The sequence does not matter as long as all four wheels are bled.

Question 4

After installing new brake pads and rotors, a technician should perform a bedding-in procedure. What is the main purpose of this process?

Accepted Answer

To deposit an even layer of friction material onto the rotor surface.

Answer

To cool down the new components rapidly.

Answer

To ensure the caliper pistons are fully retracted.

Answer

To clean any oils or contaminants from the new parts.

Question 5

A vehicle is brought into the shop with a complaint of a "spongy" or "soft" brake pedal. Which of the following is the MOST common cause of this symptom?

Accepted Answer

Air in the hydraulic brake lines

Answer

A seized brake caliper slide pin

Answer

Contaminated brake pads

Answer

A malfunctioning brake booster

Question 6

During a brake inspection, a technician notices that the inner brake pad on one wheel is significantly more worn than the outer pad. What is the most likely cause of this uneven wear?

Accepted Answer

Sticking caliper slide pins or a seized caliper piston

Answer

Worn wheel bearing

Answer

Over-tightened lug nuts

Answer

A leaking brake hose