A brake caliper fits over the rotor like a clamp (see photo above, left side). Inside each caliper is a brake pad ( a pair of metal plates that have been bonded with friction material).
When you apply the brake, brake fluid from the master cylinder creates hydraulic pressure on one or more of the pistons in the brake caliper, forcing the pads against the rotor and stopping the vehicle.
There are two types of brake calipers:
1) Floating (sliding): they move in/out relative to the rotor and have one or two pistons on the inboard side of the rotor. The piston pushes the entire caliper when the brakes are applied.
2) Fixed: These don’t move. Instead, they have pistons on the opposing sides of the rotor. They are usually for high performance and are more expensive.
Dirt or rust can build up in the calipers over time, which causes the caliper to not fully retract the pad from the rotor. This leads to excessive pad wear, inefficient fuel use and the rotors may warp more quickly. Additionally, a caliper may get stuck (seize into place) and will need to be replaced. If the caliper cannot force the brake pad against the brake rotor, you will not be able to safely stop the vehicle.
Call Keith’s Car Care today at (630) 554-8911 and set up an appointment to have us inspect your brakes & calipers.