DFFT Brakes and Braking Systems 3

Question 1

During a DFFT test, a brake drum is found to be scored with deep grooves. What is the correct action?

Accepted Answer

Replace or machine the drum if within manufacturer's serviceable limits

Answer

Clean the drum with brake cleaner and reinstall

Answer

Replace only the brake shoes and reinstall the drum

Answer

Measure the drum for roundness only

Question 2

A rear-wheel-drive vehicle's rear brakes lock up before the front brakes under hard braking. What does this indicate?

Accepted Answer

The brake proportioning valve is faulty or maladjusted

Answer

The front brake pads are worn and have less friction

Answer

The rear brake fluid line has a restriction

Answer

The rear wheel cylinders are over-pressurized

Question 3

A technician notices rust and pitting on the interior of a brake drum. What effect will this have on braking?

Accepted Answer

Reduced friction and uneven contact, decreasing braking efficiency

Answer

Increased friction due to the rough surface texture

Answer

No significant effect if brake shoes are new

Answer

Increased hydraulic pressure needed to activate brakes

Question 4

What does it mean when brake fluid has a dark brown or black color?

Accepted Answer

The fluid is old, contaminated, and has absorbed excessive moisture

Answer

The fluid is a high-performance DOT 5 silicone type

Answer

The fluid has been recently dyed for leak detection

Answer

The fluid has mixed with engine oil

Question 5

A vehicle's ABS activates during normal, non-emergency stops at low speed. What is the most likely cause?

Accepted Answer

A faulty wheel speed sensor sending erratic signals

Answer

Glazed brake pads on the front axle

Answer

A worn brake master cylinder

Answer

Low brake fluid level triggering ABS activation

Question 6

After bleeding the brakes, the pedal remains soft. What should the technician check next?

Accepted Answer

Inspect all brake hoses for internal collapse or restriction

Answer

Check the tire pressure on all four wheels

Answer

Test the engine vacuum at idle

Answer

Inspect the wheel bearing play