[Lang]

David and Ian,

I agree that this is a good modification which nobody can easily see but adds to safety. Just a comment about servos - I am a great believer in them having fitted one to my WC53 Dodge Carryall standard master cylinder. The difference was amazing, it actually stops like a normal vehicle!

This modification is bloody dangerous on Jeeps because of the axle twist pulling the steering bell-crank and of course the steering, causing violent swerving in an emergency stop. A safe jeep is one with lousy brakes!

The Jeep one being looked at on this thread is worth trying without a boost servo as combinations of sizes between master and wheel cylinders are a little tricky (but easily worked out by a bit of simple maths before fitting).

Your suggestion about boring the master cylinder(s) larger would make the pedal harder to push, not easier. This is the principle of hydraulic devices such as rams, jacks and brakes - the greater the difference between the surface area of the the pushing ram (master cylinder) and surface area of the lifting ram (wheel cylinders) the easier and more powerful it is.

Of course a master cylinder of 1/4 inch bore would be as light as a feather to lock the brakes but unfortunately the pedal would have to start its travel about your armpit to push enough volume of fluid into the wheel cylinders to move them. You see this effect in normal systems when the brakes are not adjusted up closely and the pedal goes down a long way to operate them.

Lang