***One way valve on brake booster? What to do?

Roastin944 · 02-13-2003, 08:18 PM

Hello everyone,
I have a question regarding the brake booster. You know how there is a large vacuum line going to the brake booster and how it breaks off into a few different ways and 2 go to the n/a curved rubber intake tube? Well i was wondering, since the brake booster is run off of vacuum, if boost will affect the brake booster since it will be going into it, Im not going to be braking and hitting boost at the same time so thats not any worries, i was just wondering if boost going into it is ok or not? Is it set up the same on the 951? I was thinking if the brake booster cannot have anything above zero vacuum, then i will put a one way valve that closes when it starts to push on it and opens when vacuum pulls. Anyone know what should or shouldnt be done with this? How about the 2 lines going into the intake before the throttle body? After i take those out, should i weld nipples and reconnect then to the intake pipes, boost will then now be running through those too? I think i saw on the speedforceracing kit that they disconnected both and hooked them together, but im not sure, i know someone on here has a speedforceracing kit, could you email me pics of this section of the engine bay, that would be awesome! Or just tell me how it works with that. Need to get this situated before i start boosting it, i dont want to blow brake fluid out of the brake booster or something, thanks

John

1.2gees · 1.2gees's Garage

You can run your vacuum line ahead of the supercharger. You might want to consider just going to manual, if you leave your master cylinder alone, with the 944 turbo brakes the pedal shouldn't be that hard to push.

On the 944 turbo the brake booster "vacuum" is taken from the manifold, with a y pipe and a restrictor. There's not a "check valve", from what I make of it the Y pipe acts as one. (I just threw away one after replacing ALL of the vacuum boost lines, and wow do their costs add up). Anyway you could get a check valve made for another application to have it run only on vacuum but like I said I'd just hook it up ahead of the supercharger or leave it off all together.
Ahmet

Roastin944 · 02-13-2003, 09:18 PM

Oh ok, so it is not necessary to have it, it just makes stopping easier when pushing on the pedal? So the y-pipe on the 951 doesnt keep all the boost from going into the brake booster? If i put it anywhere before the throttle body, there will not be any vacuum for it. Anyone else? Thanks for the advice!

John