Disc Brake Components
Drum Brake
Components
Components
Brake Hydraulics
Brake Repairs
Road Testing -
Symptom
/ Cause
Symptom
/ Cause
100
Surface area that brake pads squeeze against to slow rotation of tires.
Brake rotor
100
Component the brake shoes push against to slow the rear wheels.
Brake drum
100
A device that stores brake fluid and hydraulically forces it through the brake lines to the brakes when the brake pedal is depressed.
Brake master cylinder
100
Brake pads should be replaced at or below this measurement in millimeters
3 millimeters
100
Symptom: While driving 40 mph, there is a squealing noise when brakes applied
Cause: Worn brake pads (pads too thin)
200
Friction material used in disc brake system
Brake pads
200
Friction material used in drum brake system
Brake shoes
200
Alerts the driver when the brake fluid level is too low
Brake warning light
200
This specification can be found engraved into the rotor.
Rotors should be replaced before they reach this measurement and should not be “turned” (machine refinished) below this.
Minimum Thickness
200
Symptom: Brake pedal is hard to press and brakes do not seem to stop vehicle very well.
Cause: Failed brake booster
300
Part of the disc brakes, uses hydraulic pressure to apply the brake pads to the rotor.
Brake caliper
300
Responsible for pulling the brake shoe away from the drum when the brake pedal is released
Return spring
300
Flexible tube that transfers hydraulic pressure to the calipers while allowing movement of the suspension and steering system
Brake hose
300
Term for when brake rotors are no longer straight and are warped
Lateral runout
300
Symptom: Brake pedal is soft and falls to the floor when pressed
Cause: Fluid leak -or- failed brake master cylinder
400
This part allows the caliper to slide and is only found on calipers with a single piston
Caliper guide/slide pins
400
Component that all other drum brake components mount onto
Backing Plate
400
The hydraulic component that pushes the shoes into the drums
Wheel cylinder
400
Process of removing air from the hydraulic system so that the brakes will apply when the brake pedal is pressed.
Brake bleeding
400
Symptom: While driving 40 mph, there is a steering wheel shimmy when the brakes are applied
Cause: Front Rotors - Warped
500
Applies spring pressure onto brake pads to prevent squealing
Anti-rattle clips
500
Responsible for holding the brake shoes onto the backing plate while allowing it to move
Hold down spring
500
- Keeps the rear brakes from locking up during a panic stop.
- Delays the front brakes so that they apply at the same time as the rear on disc/drum brake vehicles
- A pressure switch sends an electrical signal if pressure is lost
Combination valve
500
Tool used to adjust brake shoes
Drum brake gauge
500
Symptom: While driving 40 mph, the brake pedal pulsates when the brakes are applied.
Cause: Rotor thickness variation