Audi A4 noisy power steering pump
Aftermarket one was noisy. System flushed and correct fluid used.
Replaced with genuine Audi pump as advised by power steer repair shop.
New pump noisy as well. Have replaced intake hose from reservoir and cleaned filter in reservoir.
Carried out bleeding process. Checked for air leaks before pump. Flushed all lines and cooler.
Still noisy and does look like tiny air bubbles while working steering.
Hi Russell, I would be critical of the return side also. I have had hoses fail the internal liner and create a restriction. One I had on a BMW with a hydraulic P/S driven fan had me going for several hours because an internal chunk of hose was restricting the flow. Hope this helps you.
Hi yes I did question the pressure side ,as it does seem restrictive to blow through the high pressure hose from the pump to the steel line.But have been told by power steer shop that they have restrictors in the hose.
Hi Russell, I question that they said there are restrictors in the hose. That does not sound plausible to me. Normally any restrictor or regulating valve is on the pump itself.
Hi there is a restrictor in the return right at the end of the hose where it attaches to the reservoir.But there also seems to be something in the high pressure line as you can see 2 lumps in the center of the hose.
I would recommend doing a true system flush, meaning uncouple the reservoir and run the suction hose into a container full of fresh fluid, run the return hose into a waste container, and run the system while turning the wheel. Just draining, filling and bleeding won't do it.
I have had several stubborn power steering systems over the years act the same way. Somewhere along the way I picked up the trick of pulling a vacuum on the system for about 15 minutes and it has worked like a charm each time I've had to resort to it.
How is the steering? Does the wheel turn smoothly or is it just noisy?
As stated pulling a vacuum in the system is an excellent method. It does two things, first it can remove air bubbles, and second, if it simply makes more air in the system there is a definite leak on the suction side. Any power steering system should hold vacuum.
I had an audi with the same issue and had to change fluid reservoir we cleaned it multiple times but still noisy, changed reservoir and no more noise
Agree with what Max said. I also remember an Audi with a noisy new pump. The noise went away after replacing the reservoir. We also thought the old reservoir filter was clean. Another time it was the suction hose sucking air in and the pump making a lot of noise. Took me awhile until I realized how soft and swelled the suction hose was, not sealing and allowing air to get in and mix with the…
Thanks for that.The A4 one mounts on the inner guard and can remove the internal filter from the return side and clean it. Pretty much no hidden surface on the inside when its out so is easy to clean.
I have seen Hondas do this due to the filter/screen in the reservoir being clogged, maybe Audi has this too?
Hi Russell try lifting the front of the car leave the reservoir cap off with the car warmed up and idling turn the wheel lock to lock when the bubbles clear the system is bled out. this always worked for me .
There is a service bulletin #2022583 on how to verify if you have air in the system and how to bleed it. I would still verify first that the suction line from the reservoir to the pump is not squeezed, pinched, twisted, or the inside liner of the hose has collapsed, causing any reduced fluid flow.