A website dedicated to the building of a VW based dune buggy and some other random stuff too.

Crazy Cam's Technical Bits... Brakes

A discussion of off road braking systems and modifying the beetle system for a buggy.

Basic set up

The basic VW Beetle brake set-up is a dual circuit with separate front and rear hydraulic circuits.

Buggy considerations

Due to the larger diameter of most dune buggy's rear wheels it is recommended that the stock rear wheel brake cylinders are replaced by stock front wheel brake cylinders. These have a larger internal bore, and therefore more stopping power !

Advanced off road braking systems

Since the Deathwagon will be rear wheel drive, and I intend to use it on dirt tracks normally used by 4 wheel drive vehicles (or tractors) I will need some whizzy features.

Problem

I can envisage the situation were one rear wheel is lifted clear off the ground. This wheel would then spin leaving the other wheel on the ground but with no power.

Solution

Devise a braking system where by each rear wheel can be braked independently.

Commercial solutions

There are a few commercially available products which can be used to perform this.

Cutting Brakes

These have separate mechanical connections to each rear brake and operate by levers. This does not affect any existing brake systems.
Crazy Cam says - Requires too much modification of the braking system

Steering Brakes

These fit inline with the rear brake hydraulic pipes and act as additional master cylinders. These can be controlled by either a single or a double lever, and claim not to interfere with the existing brakes performance.
Crazy Cam says - Not street legal (I think) and very difficult to hide from the MOT man

Line Locks

This is essentially a valve in the brake line. By pressing the brake pedal and operating the lever the brakes can be locked on. This is typically used for burn outs.
Crazy Cam says Dangerous - can be locked in a low pressure mode where the brake will never work !

Park Loks

Similar in operation to the line lock but the lock is realised when the brake pedal is pressed again.
Crazy Cam says Good solution, safer than line locks and can be hidden from Mr. MOT inspector!

Home-made solutions

A simple home-made system would be to modify the handbrake. This would then be able to function either on both (normally) or on each rear wheel separately. In a Beetle there are two handbrake cables - one on each side - so such a modification should be quite simple.

More details when I think of them !