A6vanilla

I had some groaning and unusual bubbling fluid in my p/s system reservoir recently. I report that the early morning groan was caused by a jammed up filter located at the inlet side of the reservoir on my 98 A6 quattro. Since the filter seemed unreplaceable, I removed the filter element in the interior of the reservoir by force, then installed a small fuel filter inline on the small hose side of the reservoir. I then replaced the old dirty fluid with new CHF/Pentosin and bled the system. I am going to replace the fluid again tomorrow to clear out the sediment and junk from the steering rack downward. I have as of yet, no further noise from the pump. The noise was caused by the filter not allowing free flow of the p/s fluid to flow back down into the pump body when the car sat overnight, leaving a pocket of air to dry the seals and cause the "frothy" liquid, which overheats things badly. If you free the airpocket and replace the filter, it tends to allow the system to completely flow with fluid and thus avoid burning out your pump. That pocket of air becomes stuck in the rack, and then recycles the problem over and over again until you clear the system and restore the fluid flow and balance.

Uncle Castro

Was yours groaning only in the morning?