What Is a Brake Caliper?
The brake caliper is a hydraulic clamp that straddles the brake disc. When brake fluid pressure is applied through the pedal, pistons inside the caliper body are forced outward, pressing the brake pads against both faces of the disc. Calipers are either floating (sliding on guide pins) or fixed (with pistons on both sides). The caliper also contains the brake hose connection, bleeder nipple and in the case of rear calipers on many vehicles, an integrated handbrake mechanism.
What Does the Brake Caliper Do?
The caliper converts hydraulic brake fluid pressure into the mechanical clamping force applied to the brake disc. The design of the caliper determines how evenly this force is applied across the pad face — uneven application causes uneven pad wear and reduced braking efficiency. Caliper guide pins (also called slide pins) must be kept lubricated to allow the caliper to float correctly and release fully when the brakes are released.
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Get My Free Fault Scan →Symptoms of a Failing Brake Caliper
A seized or sticking caliper causes the brake to remain partially applied, generating heat, accelerating pad and disc wear on one corner, and causing the vehicle to pull to one side under braking. A completely seized caliper may cause a wheel to lock or the car to veer sharply under braking. Seized guide pins are one of the most common brake-related MOT advisories.
When Should the Brake Caliper Be Replaced?
Brake calipers are replaced on failure — seized pistons or corroded caliper bodies. Caliper guide pins should be cleaned and lubricated at every brake service. Replacement caliper cost ranges from £80 to £250 per corner depending on vehicle.
If you are experiencing symptoms related to your brake caliper and are unsure whether it needs replacing, a free MotorLoom fault scan can help identify whether the component is likely at fault - giving you the most likely cause and estimated repair cost before you visit a garage.
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Related Parts
Other components that work alongside or are related to the brake caliper: