Power Brakes on a older 911?

[hahnmgh63]

Anyone know how difficult it would be to convert my '74 911 to power brakes? Would there be much sheet metal work? Thanks, MGH

[wastintime]

My boss did this conversion on his '71 track car. It's pretty darn involved, and there is some cutting and a good bit of welding. The gas tank needs to be removed, I can't remember if we had the front suspension off to make it easier or if we were doing something else, but we did take it off. He needed a different pedal cluster as well... not sure about 74s. You're also going to spend some time making spacers to elevate the thing in the trunk that's name is escaping me at the moment.... where the bar for the power brakes goes up into.

my verdict is it's pretty involved and very time consuming to do it right.

[H20911]

Jack did this on his car. pull search and he will show the metal graphed in.
here are a few pics that I saved

a new pedal assembly and rods 77+
new booster and m/c
run a vac line to the booster
new hard lines to be ran

[jorian]

Do 3 sets of lunges a day - it's cheap, you'll get the required thigh muscle and loose weight to boot

[Dennis Kalma]

I did it on my '75, basically the same cut out as what is in the pictures (I'll dig for mine). Driver in my case was the move to Turbo brakes, which needed the 23mm master cylinder and in order to keep the pedal pressure down to the point where my 5' 0" wife could actually stop properly....power brakes.

Difference is that I used a fair number (say 30) solid core rivets to mount it as I did not want the damage to nearby parts that welding typically would cause and there is very little stress on the sheet metal. Most of the force is taken up by the strap that goes from the pedal cluster to the brake booster assembly....

It's been about 5 years since I did it, not a problem since. You have to get a source of vacuum from the the engine of course, plus there is the different wiring for the stop light switches. None of it is all that diffficult, just tedious..

Dennis

[Bill Verburg]

You could also t/p the hyd. boost setup from a 993C4. it would be a little harder though

[Quicksilver]

My wife doesn't have any trouble with the brakes in my car and I took the power brakes out.
Not sure why you would consider this for a track car. You want more feel and less pedal travel for sensitive braking on a track car.

Wayne

[Eric_Shea]

I did it on mine

[MotoSook]

Originally posted by Quicksilver
Not sure why you would consider this for a track car. You want more feel and less pedal travel for sensitive braking on a track car.

Wayne

I prefer the non-boosted brakes of my '76 over my Carrera's...for the same reason.

[wastintime]

eric... are your rotors on backwards?

[Eric_Shea]

Left said left right said right...

Why?

[wastintime]

well, it's hard to tell from the pic, but it looks like the drill marks are going the wrong way, and the drilling is done in tune with the curving of the internal veins of the rotor, unless yours are straight and then i guess it doesn't really matter except for looks

[Eric_Shea]

That's the left (drivers) front. Looks good to me...

[Bill Verburg]

the drilling is done in tune with the curving of the internal veins of the rotor, unless yours are straight and then i guess it doesn't really matter

Those rotors have straight veins, not that it matters. The hole pattern can and often does go across the internal vanes.

[wastintime]

ok, just looks wrong to me, I've only seen them actually installed backwards once on a 928 that came into the shop, and it really should matter if the veins aren't straight. I've seen some hole patterns that don't go straight, i'm not saying they do, it's just that usually they all look like they're in some way curved in the same direction. Personally i think the holes drilled in a straight line look terrible... i think aj-usa sells them.

[Jack Olsen]

Boosted is better, in my opinion.

Save me from power steering -- but give me the vacuum-assisted brakes.

[wastintime]

I agree with jack on this one (with both statements)... I've driven both back to back, granted on a racetrack, and the power assisted brakes are much better, they're so much easier to control/modulate.

[Bill Verburg]

Boosted or non is highly dependant on the m/c & caliper combos employed, you really can't make a blanket statement

[khyden]

I put a brake booster on my -74. It was really hard work, but now itīs very nice to drive and works fine.

Kris