The Master Cylinder is about 8inch long and contains a plastic reservoir holding about 6oz of break fluid with two arteries. the steel break line and flexible rubber hose transmit hydraulic pressure to all brake circuit. But, whats most impressive about the master cylinder and braking system is they will bring a vehicle weighing 2,690km to a stop in a matter of seconds.


Master Cylinder are reliable and relatively trouble free. Professional quality master cylinder are precision made, some are aluminum and some are cast iron. there are few interval moving parts, rubber caps and seals, and specially calibrated spring help slide the primary piston and secondary piston. Master Cylinder are divided, each has its own circuit and tandem master cylinders have a safety feature. if one circuit leaks the other will not be affected.


There are two different circuit on Rear wheel drive vehicles, one for the front brakes, the other for rear brakes. Front wheel drive vehicles have a diagonal split system, the left front and right rear share one circuit and the right front and left rear brakes share the other. Some companies, like Volvo, have triangular circuit, with both front and left rear on one circuit and both front and right rear on the other.