How does a ABS Braker Booster work?

[paddy26 3]

I had this in my build thread but figured it would get more views here.

 

As title says, how does it work?

I know how a non abs booster works, but I'm not sure what's different for an abs one.

 

As part of my restoration I will be removing the abs system from the car.

To keep costs down I'd like to reuse my brake booster and master cylinder if possible.

I have ordered a brake bias valve which I will fit inside the car so I can adjust the rear brakes as needed.

I have already removed the original proportioning valve from the rear axle as it was rusted and not working anyway.

[paddy26 3]

Anyone?

 

I hope to start work on this at the weekend.

 

\Paddy

[Supercharged 2]

It's not much different but you do have the Outlet for the pedal sensor which you could just leave... I think it's the same size

 

The Master is different as is the res - I have a new genuine VW non ABS master for sale on here if you need... I'm just wondering if it will fit the ABS servo though - may be a different bolt pattern?

 

Obviously there is the other bits like sensors and the abs rings which could be left but all the brake pipes will need changing... why do you want to remove? strictly speaking it shouldn't pass the MOT like this as if it was factory fitted with ABS it should have it but then I think these cars are probably too old for them to know on the computer and if it's removed completely then they won't be able to tell...

[paddy26 3]

Thanks Supercharged.

I'm doing a complete removal.

I'm redoing all the engine wiring looms and the abs loom is already gone.

sensors and rings in the hubs are already gone.

i'm fitting stainless hoses and new hard lines, with an adjustable brake bias valve for the rear brakes.

i was going to reuse the master cylinder aswell and just block up the ports i dont need.

[paddy26 3]

Any more inputs before I clean my abs booster and master cylinder and install them over the weekend?

 

\Paddy

[P3rks 11]

I'd try and source a late MK3 golf (post 95) master cylinder. For three reasons.

 

1) The Corrado master cylinder is obsolete so if yours dies you'll have a harder time to find one and if you do it'll cost you. Where as the Golf one is still available, fitted to other VAG cars such as a passat so are very easy to find and they are readily available; thus cheap to replace.

 

2) The Corrado master cylinder has an outlet which is on the underside so it also has to have a bleed nipple on the top as air gets trapped. They are notoriously difficult to bleed. The Golf has that same outlet but on the top of the master cylinder so its self bleeding - no hassle.

 

3) The Corrado master cylinder is steel iirc, either way its heavy and rusts. The Golf's is aluminium and I've taken ones off cars 15+ years old which still look new.

 

You could fit this at a later date but you'll have to change the relevant pipework as the outlets are in different positions, so whilst you are renewing the pipework I'd do it now. Also, to confirm its a direct fit to the Corrado master cylinder.

 

Also. A servo from a late B4 passat is the same fitting and size as a Corrado's but doesn't have a pedal switch/sensor outlet. Perfect for your needs.

 

By the way.. This information is Correct for VR's and I've compaired it all to my 1993 VR6

[paddy26 3]

quick update on this....

 

i sourced a servo and master cylinder from a non-abs mk3 golf.

the only issue was that the corrado servo has a fork connection to the brake pedal and the golf has a ball and socket.

to fix this i cut the ball from the golf servo and threaded the remaining bar to M10. this was the same size as the corrado servo so i was then able to swap over the fork without any issues.

i never thought of taking a picture before i installed it in the car.

 

\Paddy

[P3rks 11]

Ballsy, I wouldn't trust cutting and re-threading anything brake related.