ASE A5 Brake Lines, Hoses and Valves

Question 1

After a brake pedal release, the left rear wheel continues to drag. Loosening the left rear bleeder lets a spurt of fluid escape, and the drag disappears. Which is the most likely cause?

Accepted Answer

A collapsed inner liner in the flexible rear brake hose

Answer

A deteriorated hose liner can act as a one-way valve, trapping pressure at the wheel after the pedal is released. Opening the bleeder relieves the trapped pressure and frees the brake.

Question 2

Which is the main purpose of the metering valve in a front disc/rear drum brake system?

Accepted Answer

To delay front brake application until the rear shoes have overcome their return springs

Answer

The metering valve briefly holds off pressure to the front disc brakes so the rear drum shoes can begin to move. This gives more balanced application at low pedal pressure.

Question 3

A technician is replacing a section of steel brake line on a vehicle that uses SAE 45-degree flare fittings. Which type of flare should be formed on the tube end?

Accepted Answer

A double flare

Answer

SAE 45-degree brake fittings require a double flare. The doubled-over wall is stronger and resists splitting under high pressure.

Question 4

Which is the main purpose of a proportioning valve in a brake system?

Accepted Answer

To reduce the rate of pressure increase to the rear brakes during heavy braking

Answer

During hard braking, weight shifts forward and the rear wheels unload. The proportioning valve limits the rise in rear pressure so the rear wheels do not lock prematurely.

Question 5

What causes the red brake warning lamp to light through a pressure differential switch?

Accepted Answer

A drop in hydraulic pressure in one circuit shifts the valve piston into contact with the switch

Answer

If one circuit loses pressure, the higher pressure in the other circuit pushes the differential piston toward the low-pressure side. The piston closes the switch and lights the warning lamp.

ASE A5 Practice Test

ASE A5 Practice Test

ASE A5 Brake Lines, Hoses and Valves