Remote brake booster

[dagriff]

Anyone fitted a remote booster (servo) to a non-boosted earlier 911?

I don't mean the whole swap to later style, but adding a remote vacuum booster.
I have seen it done on a lot of older Brit cars.

My 77 stops way better with the Carbon Metallic Performance Friction pads, but still needs a real hefty left foot.

[john walker's workshop]

77s had power brakes. what happened to yours? i just repaired a 77 brake vacuum hose that was full of cracks where it bends around by the trans mount and hose clamps to the tunnel tube. got virtually no vacuum at the booster because of it. pull off the front vacuum hose from the metal tube by the booster and see if it sucks your thumb real well.

http://www.ecihotrodbrakes.com/remote_booster.html

http://www.jalopyjournal.com/forum/showthread.php?t=12355

[dagriff]

Originally Posted by john walker's workshop

77s had power brakes. what happened to yours?

I think you will find that only the U.S. spec 77s had a booster. Mine is ROW (U.K.)

I guess I should put it in my Sig!

[Walt Fricke]

You can't add just the remote booster. You need to install the full package. You don't need to change calipers or rotors or most of the brake lines, if that is what you ment with the reference.

My Euro '77 2.7 also lacked power brakes. Helpfully, though, the chassis was mostly ready for them: the tunnel had the long steel vacuum tube running through it, and the firewall had the dimple in it for the big pie tin booster.

Before I got around to doing anything about adding boosted braking someone hit the car in a race and I had to replace the front clip back to about the shift lever, which I did with one from a later car, which also had some necessary reinforcing which the '77 didn't have, in non-boosted form anyway, and otherwise had all the holes and studs and so on for mounting things. And by then I had a 3.0 in the car, and it had the vacuum takeoff fitting in the engine plumbing.

With all that in place I bought a used booster/mc/housing, and a used pedal cluster, and the pedal link and also a reinforcing tension member which is part of the deal and hooks the bell crank housing to the pedal cluster. This stuff all bolted in, so all I really needed to do was find some hoses and take some spare brake line and bend it so I could route that up to where the MC now sits. Bit of a pain. I got frustrated at my inability to disassemble the MC for cleaning and inspection, so I bought a new one of those. I still don't know why it wouldn't come apart - I've gotten regular ones apart. But it wouldn't.

But with your car, and with any earlier 911, I'd suggest going to a junk yard and having the sheet metal in the area where the boosted assembly mounts cut out, leaving generous overlaps. You can then cut out a slightly smaller part of your firewall, and weld in the used piece, bracing and all. Now you can just bolt in the assembly and add hoses.

Well, sort of - you still need to pick up the vacuum from the CIS intake. I don't know just what is in the proper fitting, but it is not just a T in a line. So you'd want to source those lines from a US '77. Maybe you could just substitute whatever the 3.0s used, or you could cut out the fitting and figure out how to splice it into a suitable line.

But at least you ought not to have to run a steel tube all the way up the tunnel.

Myself, I'd just build up leg strength. I never felt I needed the boost, and I don't particularly like it either. I needed to comply with racing class rules for an updated car.

At least you now have a better idea of the project's complexity.

Walt Fricke