420motorsport. Brake Systems – Disc Brakes, Master Cylinders & Brake Parts

What the brake system components do

The brake system converts the pressure from the pedal into friction at the wheels. The master cylinder and brake booster create and amplify the hydraulic pressure, while disc brakes or drum brakes convert it into braking force. Valves control the pressure: a proportioning valve can adjust the balance between the front and rear axle, and a residual pressure valve can maintain a low pressure in the system, typically with drum brakes. On top of that come handbrakes, vacuum pumps for engines with too little vacuum for the booster, and exhaust brakes for diesel engines.

How to choose brake parts

Start with how the car is used. For daily driving, it is about smooth braking performance and low noise. For hard driving, heat tolerance is important, because overheating can cause braking performance to fade. Consider, among other things:

Use and temperature: The pad compound and rotor type should match how hot the brakes get.

Rotor type: Drilled, slotted and two-piece rotors, e.g. from DBA for the Nissan GT-R, 370Z and Corvette C6, are alternatives to solid rotors. Whether they offer an advantage depends on the car and its use.

Balance: Larger rotors or calipers on one axle can change the brake bias and may require adjustment.

Fitment: Wheels, hubs and existing calipers determine what can be fitted. Some rotors are only designed for specific factory systems.

In this category you will find brands such as Wilwood, EBC, PowerStop, R1 Concepts and Brembo, as well as complete kits, e.g. Baer Brakes' rear brake kits for classic GM rear axles. If you change calipers, check whether the master cylinder's capacity is still suitable, so that pedal travel and pressure are not changed undesirably.

Installation and maintenance

Brakes are safety-critical, so installation should be carried out by someone with experience, and the system must be bled afterwards. Use the correct tightening torques and the right hardware – for two-piece rotors, for example, separate bolts and nuts are available. Brake fluid absorbs moisture over time and can boil under hard use, which can result in a soft or long pedal. That is something different from overheated pads and rotors losing friction. So change the fluid regularly and check the wear on pads and rotors.

Frequently asked questions

Are drilled and slotted brake rotors better than solid rotors?

Not necessarily. Drilled and slotted rotors can help carry gas and heat away, but whether they offer an advantage depends on the car, the pads and the use. Solid rotors can be just as suitable.

Do new brake parts need to be approved for inspection?

It depends on the product and the car. Check the approval, e.g. E-mark or R90 for pads and rotors, for the specific part number, and find out whether changes to the brake system must be declared at the vehicle inspection.

Why does the brake pedal become soft or long?

It can be caused by air in the system or by brake fluid that has absorbed moisture and boils at high temperatures. Bleeding and fresh fluid of the right type often solve the problem.

Do I need to replace the master cylinder when I upgrade the brakes?

It depends on the change. Calipers with different piston sizes can require a different fluid volume, so the pedal travel changes. Check whether the existing master cylinder suits the new system.