Master Cylinder & Brake calliper

Master Cylinder:

the master cylinder is a control device that converts non-hydraulic pressure into hydraulic pressure. This device controls slave cylinders located at the other end of the hydraulic system.
As piston move along the bore of the master cylinder, this movement is transferred through the hydraulic fluid, to result in a movement of the slave cylinder. The hydraulic pressure created by moving a piston toward the slave cylinder compresses the fluid evenly, but by varying the comparative surface-area of the master cylinder and/or each slave cylinder, one can vary the amount of force and displacement applied to each slave cylinder, relative to the amount of force and displacement applied to the master cylinder.
The most common vehicle uses of master cylinders are in brake and clutch systems. In brake systems, the operated devices are cylinders inside of brake calipers and/or drum brakes; these cylinders may be called wheel cylinders or slave cylinders, and they push the brake pads towards a surface that rotates with the wheel until the stationary brake pad create friction against that rotating surface.



Brake Caliper:

A brake caliper is a device used to push the brake pads against the surface of the brake rotor to slow the car down.

The brake caliper works with hydraulic pressure, every time you push the brake pedal, the brake fluid travels from the brake master cylinder to the brake proportioning valve ( when the car is not equipped with ABS ), if the car has ABS, the brake fluid travels through the ABS Hydraulic control unit, and from there the brake fluid travels inside the brake lines all the way to the brake calipers, this hydraulic pressure pushes one or more cylinders inside the brake caliper against the brake pads, this pressure forces the brake pads to make contact with the brake rotor, the force will ve relatively equal to the force applied by the driver to the brake pedal.

- The bad brake caliper are the following:
1- Brake fluid is leaking past the seals in the caliper pistons.
2- The car always pulls to one side when the brakes are applied ( signs of a sticking brake caliper )
3- Premature brake pads wear. ( Also caused by sticking brake calipers )