disc brakes
TRANSCRIPT
Automotive Disc Brakes
Disc Brakes
Disc brakes are fairly simple to work with, once you know the parts and their functions. Typically, there are 4 main parts of a system:Mounting BracketRotorCaliperPads
Mounting Brackets
Mounting Brackets are used to hold the Caliper in place.
Other than keeping the surface clean and free of rust and road grime, there is very little to be done with this part
Rotors
Rotors are metal discs supported by the suspension. The Calipers clamp on to them to slow their rotation, and then slow or stop the car
Vented Rotor
These are the VENTS
Vented Rotors
Vented Rotors have Fins in the spaces between their machined surfaces. These spaces allow air to pass through, which helps carry heat away.
Nonvented Rotor
Non Vented Rotors are used on smaller vehicles, and have no cooling fins
Non Vented Rotor
Rotor Repair
We will get back to these Rotors later concerning what you can do as a repair on them.
Calipers
Calipers are the housings that contain the Pistons and the Brake Pads. The Calipers are connected to the Hydraulic System, and hold the brake pads to the Rotor
Caliper Types
There are 2 types of Calipers
Fixed
Floating
Fixed Caliper
Fixed Calipers are disc brakes that use a caliper that is FIXED in position and does not slide. They have pistons on both sides of the disc. There may be 2 or 4 pistons per caliper
Fixed Caliper
Motorcycles and some import trucks and cars use this type
Sliding Caliper
Much more commonSingle PistonEasier to work withOn “inboard” side of caliper
Clean, Floating Caliper
Floating Calipers
Operation
Piston applies pressure to Inboard pad. As the pad contacts the rotor, the caliper slides along the pins, pulling the outboard pad into contact.
Caliper
Rotor
Piston
Brake Pads
Brake Line
Sliding caliper in operation
Parts of a Caliper
Seal
The rebuild kit will have a new O ring, and a Dust Seal
Piston
The Piston surface should be smooth and clean. This one is pitted, and needs replaced.
Adjustments?
•Disc Brakes will automatically self-adjust.
•As the Pads wear, the caliper piston will not retract as far
•This leaves a larger amount of brake fluid in the caliper, causing the master cylinder level to lower
Caliper Slides
Notice where the brake pads and calipers slide on the pin and the mount
Caliper slides
Since parts need to slide, these areas should be clean of dirt and rust,
Cleaning Caliper
With the caliper off, I would use a wire brush to clean the rust off, then use a brake cleaning solvent to wash the sliding area.
Wear Indicators
Brake pads wear, and most people never check them. So, something was put on the pads to make a noise, since most people will have a noise checked out.
Diagnosis
Several different types of Complaints
Noise
Pulsation
Pedal travel
More later…
Brake Noise
Wear Indicator
Brake Pulsation
Usually a warped Rotor
Rotor needs trued on a brake lathe