Six Pistons Brake Caliper Fit 362*32mm Dragon Slot Disc For Mini R58

What is a brake caliper?
First, let’s take a look at your brake system and understand what a caliper does. A caliper is a component of a disc brake system - the most common on today’s passenger vehicle. That system relies on hydraulic pressure to operate. When you press on the brake pedal, force is exerted through fluid inside a network of hoses and tubes to the wheels. Attached to each wheel is a heavy metal disc called a brake rotor. As your wheels roll down the road, the rotors spin with them. Sandwiched around each rotor is a pair of brake pads. Those pads are suspended in a hydraulic clamping mechanism - the caliper.

Every time you step on the brakes, the calipers squeeze the brake pads against the rotors in the same way someone in a wheelchair might grab the wheels to slow down. A bicycle works in a similar fashion. When you grab the brake lever, a cable actuates a caliper to squeeze a pair of rubber brake pads against the sides of your bike wheel. In each case, friction is created and the kinetic energy of a body-in-motion is converted to thermal energy to slow you down and bring you to a stop.

How to change a brake caliper
01 Securely jack up the vehicle, using axle stands and wheel chocks and remove the road wheel.

02 The carrier is usually bolted to the hub with two bolts, these can be left in place if you're only changing the caliper – but will need to be removed if you're also changing the disc.

03 The caliper is secured to the carrier with two bolts, usually with allen heads, which secure a pair of sliding pins in the body of the caliper.

04 By removing the allen bolts you will be able to prise the caliper carefully off the disc. It may be tricky to remove, so be careful if you're using a pry bar.

05 With the caliper removed the pads will pull out – they're often held in place by clips.

06 The brake line needs to be carefully removed from the caliper. You will need a receptacle to catch any brake fluid that will spill out (do not get this on the paintwork).

07 With the new caliper ensure the piston is pushed back into its cylinder with a pair of water pump pliers, a G-clamp, or similar. Rear pistons are often of the 'wind-back' variety and need to be pushed back into the cylinder with a brake wind-back tool. These are cheap to buy, and easy to use.

08 The pads can then be refitted to the caliper (with any necessary clips or pins) and the caliper mounted on the carrier.

09 Refit the caliper sliding bolts and check that they're in good order and slide smoothly.

10 Spin the hub and make sure that the calipers are correctly located over the disc, with no binding (some light binding is to be expected).

11 With all the bolts secure the brake hose needs to be reattached, and the caliper bled to remove the air.

12 Follow the usual bleeding procedure (either with a one-person bleed kit, or with the help of an assistant, and be sure to keep the brake fluid reservoir topped up to the correct level.

13 Check all the bolts before reattaching the wheel and torquing the wheel bolts/nuts to the specified level.

14 Be aware that the brake pedal may need several 'pumps' to bring the pad into contact with the disc. Drive carefully and ensure that the brakes function correctly