Brakes
You can have all the power in the world, but at some point you're going to want to slow your E30 down. When it's time for some middle-pedal action, get to know what your brakes up are up to.
Contents
Overview
All E30s are fitted with a hydraulic braking system. When the pedal is pressed, fluid is pressurised by the Master cylinder to send fluid to each wheel. To help, extra pressure is generated by the servo, driven by the engine. This pressurised fluid powers the braking system, which on all E30s comprises of front discs and either rear discs or drums. A the front, the brake fluid will pressurise two calipers, which will squeeze pads against the discs to convert the kinetic energy of the rotating disc into heat. To a smaller degree, cylinders on the rear will press shoes against the inside face of the drums to achieve the same effect.
When you want the car to stay still, a cable-operated handbrake will lock the rear shoes in place. On cars fitted with rear discs, small handbrake shoes work on the inside of the rear disc.
Keeping all of the components fresh and leak free will help massively in preventing car/tree interactions.
Components
Brake Pedal
Brake Servo
Master Cylinder
Brake Fluid
Brake Lines
Brake Hoses
Calipers
Discs
Pads
Drums
Cylinders
Shoes
Handbrake
ABS
Main article: ABS
Servicing
No brakes = no car. But you don't want to get into a position where you don't have any brakes, so preventative maintenance MUST be done regularly. The following parts should be inspected and replaced regularly
Common Problems
Pulling to one side
Squealing
Upgrades
Main article: Brake Upgrades
The stock braking system fitted to the 325i and all Tourings is a perfectly capable braking system for the E30, no matter how aggressively you drive. However, if you're planning to race your E30, or you've changed your engine to something more powerful, it's worth looking at your options.
Remember, bigger doesn't always mean better; massive discs with 4- or 6-pot callipers will add a massive amount of weight to your vehicle, especially its suspension, and you may have difficulty finding wheels that fit. It's often enough just to fit racing-spec pads and discs, and keep your system in top performance with regular servicing.
Learn more about upgrading your brakes.