Divorced brake booster idea.

[jaluhn]

This is something that is a direct take off on the hydroboost versus vacuum thread, but it's diffent enough it warents it's own thread. One of the reasons hydro seems to be popular is that it takes up far less room. Well, one of the things I was thinking of was to use a divoced booster. These are long used in older heavy trucks, and also I've found on 60's 122 volvos, and probably other stuff. The basic idea is that you have a conventional master clyinder mounted on the firewall, and then have a booster unit mounted else where, and hydraliclly driven. The real comercial ones are really cool, and they're built where the standard master operates a small slave that runs a piolt vavle which then actuates the vacuum booster, which then pushes a second master. They also have a smaller vacuum diaphram which gives you feedback to the petal, and the hydralics are interconnected so it still works with no vacuum. These are very cool when they work, and very powerful, but rare and most of the ones they made were either too large or too small for our use.

So, the idea I had was to build one. Rather then monkey with the interconnected hydralic, I was thinking you could just do it mechanically. Basically, the idea would be to use a standard master clyinder in the stock location, then have another one mounted where it pushes on the pushrod of a vacuum booster and master. The slaved master would pretty much just be taking the place of the brake petal, exept it would allow you to mount the booster anywhere on the vehicle. The slaved master would obviously need some mods to make it work, or possibly you'd have to custom build something, but I think it would work. You could also changed the petal feel / braking strength by changing the sizes of the various clyinders, and it would make it really easy to use diffent brakes. Just use the stock brake system to drive the booster, then have the booster drive the apropriate master for the axles. I'm sure there's some technical issues that would have to be resolved, and things 'm overlooking, but I think the idea is sound. What do ya'll think?
-John

[Grandpa Jeep]

I have thought of doing this myself. I thought it would probably work especially well for me since I have an under the floor single master cylinder. You could probably use a clutch slave cylinder on the other side of your booster too so that would probably be pretty easy. The thing I didn't like about it is it introduces a third failure point. The other thing I wasn't sure of was how to bleed the thing if the slave was higher than the master, which in my case it almost had to be.

[jaluhn]

If the slave is higher than the master, it shouldn't be a problem. The air will rise, so just open the bleeder and it'll pump out.
-John