Power steering groaning noise

[Mr. BILL]

My son's '90 515 makes a groaning noise when you turn the wheel until it warms up. It sounds like it's low on fluid (ATF) but it's not. The fluid in the resevoir is all foamy also.

Could this be from the screen in the resevoir tank being clogged? Can I clean it, or is a new one needed? Thanks

[Macv]

This happened to me a while back, the foaming and all.

I didnt really look into it though. I simply drained it. On my 540i theres a hex nut and a drain plug. A catch pan grabbed most of it, not that it missed ... but it didnt drain 100% for some reason. Then I just topped it off again. It was still the same for awhile but it has greatly improved and I no longer hear the sound or feel the rumble.

Im not sure how you'll deal with the 515 as I'm not sure if it even has a drain plug. I've heard it doesnt anyways. Someone tell me I'm wrong...

[shogun]

I replaced the filter insert in the hydraulic fluid reservoir last Saturtday, that helped too. I think it was the first time the filter was exchanged after 18 years.
http://www.autohausaz.com/search/productx.aspx?sid=1i502m55rwephdycxrgycu55&makeid=800003@BMW&modelid=1012037@525I&year=1990&cid=26@Steering%20System&gid=7292@Power%20Steering/Hydraulic%20Filter
I assume you have bleeded the system already and have enough fluid in the system.

[mamilapon]

Your system needs bleeding. Jack front end right up, Pull cap off PS reservoir, Start engine, and very gently turn steering wheel from lock to lock about ten times.Add fluid if required. Good luck!

[Mr. BILL]

Thanks I'll give it a shot

[Mr. BILL]

Follow up...
I still had the problem, so I bought a new tank. I installed it and bled the system as suggested. However, I'm still getting the groanong noise.

Any other suggestions? Hoses? pump?

Thanks