Vacuum Brake Servo

[Rusty]

Any BTDTs on swapping to vacuum brake assist? I though I'd start looking into it. I see that 034 do the parts, having looked on the family ablumen, it looks like they're off V6 variants.

The high pressure side of things runs the brakes only and then the lower pressure runs the PAS, is this correct?

If anyone has a suitable set of parts to fit vacuum assist, then please let me know

[Rusty]

No one

[Error404]

Hmm, I didn't realise it took care of the PAS too, sounding more appealing now....
Perhaps better off asking on Motorgeek mate, I remember reading that a few people on there have done it

[Rusty]

You'd have to leave the PAS pump in place and then sort something out with the high pressure side of things. The vacuum servo then takes care of the brakes. If needs be, a bypass pipe could replace the servo. I'm just fed up with the spongy feel on the brake pedal. Lots of other cars have a much nicer feel with nowhere near as much work as the S2 has received. Will have a look on MG

[terrybullwon]

Better still use a merc A class electric pas pump bin the belt driven vaine pump. Ditch the oem
Pedals get a Ap pedal box and run the correct masters for your brake set up. But you are still stuck with a old
ABS system?

Maybe Alex you can bin your ABS?

[Kieron20V]

I'll be experimenting with this soon, using a 16v servo and mc.

[Rusty]

MC is smaller than S2 so that's not a good idea. S2 MC should fit though. I'll e trying one in a mk.2 Golf soon

[siV6Qcoupe]

You remove the pistons and springs under the large cross-head screws on the front of the PS pump so that it does not generate pressure to the brake system. Remove the bomb and hydraulic lines and close off the return at the steering rack and bung the feed to the bomb. Replace the brake actuator with one from an Audi 80 B3/B4 with a matching MS - all a direct fit onto the bulkhead and run a large vacuum line with one-way valve from the inlet manifold to the vacuum actuator.

[Error404]

thats how I'd seen it done before

I promised myself I'd go to vacuum brake assist and electric PAS pump the next time my servo went bad since new servos are not affordable and there is a limit to the life span of used ones.. I've done a quite a bit of research into the PAS side of things so good to hear that the vacuum end isn't too much of a PITA

[Pat D]

Has anyone gone and fit a vacuum brake set up? I'm wondering if the master cylinder sticking out further would cause any dramas or make a tight fit for other items?

[Error404]

I don't think there will be any issues Pat. RE2500 on the forum has done this on his RHD car with an ABY fitted and don't think he has any problems.
With what you're going to be running I would just make sure you have a good heat shield for the master cylinder

[Pembo]

I run vacuum servo on the rally car. Just run the vacuum pipe , with a one way valve which is usually fitted in the 'hard' tube, to a 'T' on the intake. I did have a 12v electric vacuum pump but did away with that. To be sure you can fit a vacuum gauge too! No 'bomb' either to great brakes. Master cylinder fits to the servo perfectly. PM me if you want further details.

[AndyP]

I run vacuum servo on the rally car. Just run the vacuum pipe , with a one way valve which is usually fitted in the 'hard' tube, to a 'T' on the intake. I did have a 12v electric vacuum pump but did away with that. To be sure you can fit a vacuum gauge too! No 'bomb' either to great brakes. Master cylinder fits to the servo perfectly. PM me if you want further details.

Which master cylinder did you use?

[Pembo]

Currently using a 7A master cylinder which 'looks' physically larger but not too sure of piston/seal sizes. I run RS2 big reds calipers on the front and Cayman S 4 pot calipers on the rear. Hydraulic handbrake too and all is sweet. No ABS, No bomb just servo which came off a 10v n/a quattro but load available to chose from. Great pedal no fade and I use Castrol SRF Racing fluid.
http://www.facebook.com/alan.pembert.../photos_albums

[Error404]

I have a 10v / 2.0 16v unit waiting to go on my car.
My 20v MC which is the same as an S2 one is a straight fit as Pembo says.

The p/n is 8A2 612 105 A