What are Brake Calipers?
The hydraulic clamp that squeezes the pads onto the disc.
Simplified animation — not to scale.
In plain English
A brake caliper is the metal housing that sits over the brake disc and holds the brake pads. Inside it are one or more pistons driven by hydraulic fluid. When you press the brake pedal, the pistons push the pads onto the spinning disc, creating the friction that slows your car.
"Think of a bulldog clip clamping a spinning CD. The clip is the caliper, the pads are the rubber tips, and your foot on the pedal is what squeezes it shut."
How it works
Each wheel has its own caliper. Pressing the pedal sends pressurised brake fluid down the lines into the caliper's piston(s). The piston pushes the inner pad against the disc; on a sliding caliper the body itself then slides and pulls the outer pad in too. Release the pedal and the seals pull the piston back a fraction so the pads stop dragging.
Signs of trouble
- ⚠Car pulling to one side under braking
- ⚠A wheel that gets very hot or smells after driving (seized or sticking caliper)
- ⚠Uneven pad or disc wear on one side
- ⚠Brake fluid leaking near a wheel
- ⚠Squealing or grinding from one corner
- ⚠Spongy or sinking brake pedal
£140 – £430 per caliper (fitted)
Always get a written quote. Prices vary by car, region, and parts brand.