Ch. 80 PowerPoint

Define these Technical Terms using the textbook:

1. bleeder screw

2. brake caliper

3. brake disc (rotor)

4. brake drum

5. brake fluid

6. brake hoses

7. brake lines

8. brake pads

9. brake shoes

10. master cylinder

11. parking brake

12. vacuum booster

13. wheel cylinder

Answer these discussion questions using the textbook:

1. What is the difference between a proportioning valve, a metering valve, and a combination valve?

Read the chapter summary below:

■ Automotive brakes provide a means of using friction to either slow down, stop, or hold the wheels of the vehicle.

■ A brake pedal assembly is a foot lever for operating the master cylinder and power booster.

■ A master cylinder is a hydraulic piston-type pump that develops pressure for the brake system.

■ A brake booster is a vacuum or power steering operated device for assisting brake pedal application.

■ Brake lines are metal tubing and rubber hose for transmitting pressure to wheel brake assemblies.

■ Wheel brake assemblies are devices that use system pressure to produce friction for slowing or stopping wheel rotation.

■ Braking ratio refers to the comparison of front wheel to rear wheel braking effort.

■ A hydraulic system is basically a system that uses a liquid to transmit motion or pressure from one point to another.

■ The cup and piston in the master cylinder are used to pressurize the brake system.

■ The dual master cylinder, also called a tandem master cylinder, has two separate hydraulic pistons and two fluid reservoirs.

■ Power brakes use a booster and either engine vacuum, electric pump, or hydraulic pressure to assist brake pedal application.

■ Brake fluid is a specially blended hydraulic fluid that transfers pressure to the wheel cylinders.

■ Brake lines and hoses transfer fluid pressure from the master cylinder to the wheel cylinders.

■ The piston seal in the caliper prevents pressure leakage between the piston and cylinder.

■ The floating caliper disc brake is mounted on two bolts supported by rubber bushings.

■ The bleeder screw provides a means of removing air from the brake system.

■ The primary brake shoe is the front shoe. It normally has a slightly shorter lining than the secondary shoe.

■ The secondary brake shoe is the rear shoe. It has the largest lining surface area.

■ A metering valve is designed to equalize braking action at each wheel during light brake applications.

■ A proportioning valve is also used to equalize braking action with front disc and rear drum brakes.

■ A combination valve is a single unit that functions as a brake warning light switch, a metering valve, and/or a proportioning valve.

■ Emergency brakes, also called parking brakes, provide a mechanical means (cable and levers) of applying the brakes.