Hydraulic system problems ('85 5000 turbo)

[Ameer Antar]

Well, looks like I figured out the problem. I finally decided to replace the accumulator b/c I felt that was a weak link in the system (recharged bomb). Sure enough, after replacing that, the system works properly now. No more check system light and decent power assist for steering and brakes. Also, the fluid level does not seem to change much.
 
So it looks like this is a different failure mode of the bomb. Looking at the diagram on the SJM site, my guess is the check valve that prevents fluid from going back into the pump might have been leaking. That maybe why I noticed fluid leaking from the new pump and other areas in between the accumulator and pump.  I wonder if the pump was damaged at all b/c of this?
 
Thanks for everyones help. Hopefully this info might be useful to someone with similar symptoms in the future.
 
-Ameer
 
-------------------- Original Message --------------------
From:Kneale Brownson [kneale at coslink.net]
To:audi at humanspeakers.com, Ameer Antar [antar at comcast.net]
Cc:Quattro List [quattro at audifans.com]
Date:8/17/06 3:35:48 PM
Subject:Re: Hydraulic system problems ('85 5000 turbo)
If there's air in the hydraulics system, it usually manifests itself as a
froth in the reservoir. Bleeding air from the system is done with the
wheels off the ground, the engine running and the steering wheel being
turned lock to lock quickly and repeatedly.
At 02:38 PM 8/17/2006 -0400, Huw Powell wrote:
>> The power assist does seem to randomly change.
>
>> Also, I noticed that the fluid level in the reservoir changes a lot.
>
>Without being an expert on this particular system, I would have to say
>my first suspect here is a lot of air still in the system. It probably
>moves around, and ends up cavitating the pump while its running,
>killing, or at least randomizing, your pressure and assist.
>
>I do believe I have read here that bleeding the system is a complex
>process (but that might have been the cooling system!).
>