ASVAB Automotive Information Practice Test 562149

Questions 5
Topics Brakes, Connecting Rod, Cylinder Arrangement, Transfer Case, Wheel Hub

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.

Connecting Rod

A connecting rod employs a wrist pin to link each piston to the engine's crankshaft.

Cylinder Arrangement

Cylinder number and arrangement depends on the purpose of the engine. Smaller (four and six cylinder) engines in front-wheel drive vehicles often use an inline design which orients cylinders vertically over the crankshaft and aligns them in a row. Other common orientations are a horizontal/opposed design which places cylinders flat facing each other with the crankshaft between them and a V-type design common in six and eight cylinder engines that features one cylinder head per block of cylinders oriented at a 60 to 90 degree angle to each other with the crankshaft at the bottom of the V.

Transfer Case

The transfer case splits engine power between the front and rear axles of four-wheel drive vehicles.

Wheel Hub

The wheel hub is the mounting point for the wheel and tire assembly. The wheel hub can rotate while being held stable by the steering knuckle which applies the motion of the control arms to the wheels.