AT313 Unit 2 Test Review

Technician A says that the most common type of power assist unit is the hydraulic unit. Technician B says that the power assist unit is always installed between the firewall and master cylinder. Who is right?

• A only
• B only
• Both A and B
• Neither A nor B

A difference in pressure will move a diaphragm toward the side with _____ pressure

• more
• less
• stable
• the same

A vacuum check valve allows airflow in _____ direction(s).

• one
• two
• three
• none of the answers are correct

Technician A says that the Hydro-boost system is no longer used on automobiles. Technician B says that the Hydro-boost system has been largely discontinued in light trucks. Who is right?

• A only
• B only
• Both A and B
• Neither A nor B

Pressing on the brake pedal moves the spool valve by way of a(n) _____

• screw jacl
• bell crank
• lever
• inclined plane

Technician A says that brake fluid is used to pressurize the Hydro-boost system. Technician B says that power steering fluid is used to pressurize the Hydro-boost system. Who is right?

• A only
• B only
• Both A and B
• Neither A nor B

When a vacuum brake unit seems to have no power assist, what should the technician check first?

• the intake manifold bolts
• the vacuum hose
• power unit internals
• the pushrod length

If the vacuum booster seems to have no reserve (power-assisted stops after the vacuum source is lost), what is the most likely problem?

• Defective diaphragm.
• Defective control valve.
• Defective check valve.
• Loose pedal linkage.

If a special holding fixture is not used to hold the vacuum power assist as the two halves are separated, what could happen?

• The two halves could fly apart with great force.
• The diaphragm could stick to the front housing.
• The return spring could be bent.
• Nothing

If a special holding fixture is not used to hold the vacuum power assist as the two halves are separated, what could happen?

• The two halves could fly apart with great force.
• The diaphragm could stick to the front housing.
• The return spring could be bent.
• Nothing