Early type brake pressure regulator

[Rusty]

I'm after the early type brake pressure regulator fitted to pre 92 quattro cars. It sits in front of the ABS unit. I'll dig out a pic and part no tonight.

[john bowden]

im after one as well let me know how you get on

[Error404]

It sits in front of the master cylinder on early cars.

What is the difference between the two different parts Andy?

For reference:
early 893612303A
late 8A0612303

[dominator]

I have both of them.

[Rusty]

From S2central, all in Bar:-

Front___Rear up to 92___Rear after 92
_50______30 - 35_______37.5 - 41.5
100______45 - 50_______51.5 - 57.5

So, early type reduces brake pressure to the rear by quite a bit.

Ideally, I'll fit an adjustable one but wanted to try off the shelf first, as it'll be a lot neater and there's a question mark about the adjustable regs with ABS. I'll be plumbing it in before the pump, as per the OE one, so that's perhaps not an issue.

[Error404]

Surely the later type will be better for you with your rear brake upgrade? Or are you starting to lock up?

I want more rear bias! Its a same I just refitted mine & bled the brakes

[Rusty]

An extra 30mm dist radius takes care of that. With the ABS off, the rears lock up like a hydraulic handbrake on a rally car! not ideal. Bigger rear brakes mean more heat capacity, so more consistent braking. There's only so much grip available, so with the ABS off, I want the fronts to lock first (for obvious reasons).

[Error404]

I wonder if you can adjust it using that threaded nut on it?

[Rusty]

Oh yes, where's that? Pic? It may be underneath on mine, as I can't see a part number on the top or front.

[Error404]

There is a big hex headed plug on one end, I assume that is used to set pre-load on a valve spring or something inside. I didn't want to start messing with it though.

[Rusty]

Need to get hold of one and see what it's made of...

[s2driveruk]

An extra 30mm dist radius takes care of that. With the ABS off, the rears lock up like a hydraulic handbrake on a rally car! not ideal. Bigger rear brakes mean more heat capacity, so more consistent braking. There's only so much grip available, so with the ABS off, I want the fronts to lock first (for obvious reasons).

Sounds....interesting!!! Be a proper ditchfinder in an emergency stop lol

[Rusty]

With the ABS on, it's absolutely not a problem. I'm looking in to taking the ABS off for track.

[Rusty]

Anyone got one of the early type?

[Rusty]

Bump, still after one of these - 893612303A