I bought the car about 6 weeks ago with 89,000 miles. The PS pump was replaced about 3 months before I bought the car. The car was rarely driven the last few months by the PO.
A few days after I bought the car the PS starting moaning and groaning loud. My mechanic sucked the PS fluid out and refilled and that fixed it for about a month. It's started again. Before I go further, I'm thinking of flushing it again. Thinking there's still some crap in the fluid.
I see 2 methods for flushing, one where you remove the resevoir and flush (doesn't seem much room on my car to get the resevoir out on my car) and one where you disconnect the hose at the radiator. Which method is best? Is either waybetter than just sucking out the fluid from the resevoir several times and running the engine after each top off?
You NEVER need to flush the PS fluid on an audi, its mineral oil, meaning it will evaporate over time. So it moaning just means its low on fluid. What you need to do is remove the cap top it off, then with the engine running turn the wheel lock to lock several times over to aerate the fluid. You should see lots of bubbles, when the bubbles stop then you can put the cap back on.
One thing I forgot to mention is that it doesn't do it all the time, but most of the time. While driving the the car, it can come and go. Because of this, I was thinking there was some debris left from the PS pump replacement a few months ago.
If there is a leakage somewhere - pipes, pump itself - it starts getting air into the liquid, the air is the reason of howling. It disappears while driving (does the same as auditech79 said), but returns back after being parked for some time.
You have to inspect to whole system for leaks and potentially replace the pump ($200 for the new one or $40 for repair kit).
I just checked my records the pump was replaced a year ago.
I aerated turning the wheel back and forth with the top off for about 10 minutes. The froth is still there. I let the car sit while the bubbles cleared & after a short drive the noise and bubbles come back.
How long should I try aereating before I take it to a mechanic to inspect the whole system?
The fluid is brown in color and looks like there's air in it.
You know a month ago my mechanic sucked the fluid out a few times and poured new fluid in. The fluid was clear, looked like mineral oil. This cleared the problem for awhile.
As I know (guys please correct me), driving with the air in the pump (completely no liquid) will break the pump. I was driving for 3-4 weeks with this sound, periodically adding the liquid.
Power Steering Flush
