5000CS, leaky steering rack

[Stephen Sherman]

Our 87 5000CS Avant has been relegated to snow car status for several 
years now. It is amazing that at almost 25 years old, it is still 
running and doing fairly well, cosmetic concerns aside.

This winter there has been a steady leak of brake/steering hydraulic 
fluid. Getting worse. I have not pinpointed the cause, but it appears to 
be coming from the steering rack itself. It's now at the point of going 
down 1/2" in the reservoir in a 30-50 mile trip.  I had moved to filling 
it with plain mineral oil (because the pentasin stuff is just too pricey 
to keep up with this leak).  However at the current rate this means 
refilling every day or two when using it, up dramatically from the once 
every few weeks earlier in the season.

I know the "right" way to fix this is to put in a new/rebuilt steering 
rack. Only problem with that is I am not sure that I am willing to put 
that amount of time and $$ into this car. However I would like to use it 
for the rest of this winter (another 3-4 months).

So my question is, are there any "quick fixes" which might give a few 
more months of use. I see that for "standard" power steering systems 
there are tons of additives that will swell seals and fix leaks. Does 
any such thing exist for Audi systems? Any other alternatives?

TIA