Bomb and PAS-pump? Audi 100=Audi 80?

[Henka]

Can I use the following parts for my S2 ABY:

PAS Pump from Audi 100/A6 7/93-7/95

Bomb from Audi 100 2/88-12/90

Thing is - these parts all look the same as the ABY bits....

[porkkis]

Pas pump yes probably, but it's not the same oe number!
Bomb is the older type in that car so not that.

[Henka]

Well I've thought this through. The pump I looked at had no outlet for the brakes so - no worky. The bomb? Well... Is there any cheaper option than the Audi unit?

Is there something I can do about this whole deal. Like upgrade to another system or what ever...

[porkkis]

Drill a hole on the lower half of the bomb and weld a check valve adapter and refill 70 bar nitrogen.
Careful with the drilling as the diaphragm sits usually on the bottom so don't drill the rubber!

Or if your legistlation permits put a vacuum servo and 75bar pump... our does not.

[Henka]

Ah... You mean convert to vacuum? So the authoritys in Finland actually keeps track on that? Hey, in Sweden you can get away with almost anything... Are they really that strict?

What pump should I use (what model!) and what kind of servo? What about newer A4/S4/RS4? Are they vacuum or hydraulic?

[porkkis]

I'd use V6 CQ vacuum servo in S2. And pump from a a90. Actually you should also change the steering rack, but I would not bother. Pressure drops from 100 bar to 75 bar and steering might be a bit heavier.

And yes. They're strict. Registration info includes the brake system type and servo type.

All older turbo audis are hydraulic, I think. Newer ones might be vacuum.

[Henka]

Yeah well a servopump from a A4 is avaliable at 100bar and at 110bar (according to ETKA). But how do I fit the vacuum pump? Won't the IM be in the way? I need pics.

This is an interesting thought, definently. For now I'm going to try and find a good (cheap and clever) solution to the brake bomb problems. I'm going to meassure the pressure in the pump this weekend to see if it's at a higher level that it should be (indicating that the valve in the bomb is toast as my pump is leaking eventhough it shouldn't!)