ASVAB Automotive Information Practice Test 770872

Questions 5
Topics Brakes, Compression Stroke, Engine Block, Muffler, Springs

Study Guide

Brakes

Brakes utlize friction to slow vehicle tires. Drum brakes employ a cast iron drum that roates with the vehicle axle. When hydraulic pressure is applied to the brake assemblies at the wheels, internal pistons expand and push brake shoes outward into contact with the brake drum slowing the rotation of the axle. More powerful disc brakes operate by pinching a rotating disc betweeen two brake pads and allow for a larger surface area to contact the disc, provide more force, and are more easily cooled.

Compression Stroke

During the compression stroke, both intake and exhaust valves are closed as the piston begins moving back up from the bottom of the cylinder (bottom dead center or BDC). This compresses the air-fuel mixture in the combustion chamber which also makes it hotter.

Engine Block

The engine (or cylinder) block is the large casing that contains the cylinders and many of the internal components of the engine.

Muffler

The muffler follows the catalytic converter and absorbs sound to help quiet load exhaust. It is followed by the exhaust pipe which is the final exit point for exhaust gas from the vehicle.

Springs

Suspension springs are made with wide gap coils of rigid steel cable and both hold the vehicle chassis up off the ground and absorb energy from wheel movement making for a smoother ride.