A caliper is a crucial part of your car's disc brake system. Its job is to slow down and stop the car by squeezing a pair of brake pads against a rotating disc, called a rotor. When you press the brake pedal, hydraulic pressure forces pistons inside the caliper to clamp the pads onto the rotor, creating friction that converts the car's kinetic energy into heat, bringing the wheels to a halt. Without a functioning caliper, your brakes would fail.
There are two main types of calipers you'll encounter:
- Floating Calipers: Common on most everyday passenger vehicles. These have one or two pistons on the inner side of the rotor. When pressure is applied, the piston pushes the inner pad against the rotor, which then pulls (floats) the entire caliper body to apply the outer pad. They are simpler, lighter, and more cost-effective.
- Fixed Calipers: Typically found on high-performance or luxury cars. These calipers are rigidly mounted and have pistons on both sides of the rotor. When you brake, pistons from both sides simultaneously clamp the pads onto the rotor. This design provides more even pressure, better heat dissipation, and superior braking performance, especially under heavy use.
Recognizing a failing caliper is key for safety. Common symptoms include the car pulling to one side during braking, a spongy brake pedal, unusual grinding or clunking noises, or fluid leaks near the wheels. Maintenance is straightforward but critical. During brake pad changes, it's wise to have the caliper slides and pins cleaned and lubricated to ensure they can move freely. A seized caliper can lead to uneven pad wear, reduced fuel economy, and dangerous braking imbalance.
| Feature | Floating Caliper | Fixed Caliper |
|---|
| Piston Placement | Pistons on one side only | Pistons on both sides of the rotor |
| Cost | Lower cost to manufacture | More expensive |
| Performance | Adequate for daily driving | Superior braking power and feel |
| Heat Management | Can be prone to brake fade under stress | Better heat dissipation |
| Common Application | Most standard family cars | Sports cars and performance vehicles |
| Weight | Generally lighter | Heavier |
