power steering frozen- need help

[werminghausen]

My power steering doesn't work 100%. It works may be 50% or 30%. Steering is very hard and heavy. My wife can hardly manage the force necessary. It is tough to drive. It seems to get better after half an hour driving but still not good.
Sure it is freezing cold in Boston (minus 10 Celsius) but I haven't had this problem before.
What might be the reason? Is there a filter in the system that can clog and reduce PS?
Any idea? Martin

[genphreak]

My power steering doesn't work 100%. It works may be 50% or 30%. Steering is very hard and heavy. My wife can hardly manage the force necessary. It is tough to drive. It seems to get better after half an hour driving but still not good.
Sure it is freezing cold in Boston (minus 10 Celsius) but I haven't had this problem before.
What might be the reason? Is there a filter in the system that can clog and reduce PS?
Any idea? MartinChange to synthetic fluid if yours uses Dexron. Not sure if there is a synthetic replacement of CHF, but probably. You have to drain the whole lot from the low points if not pump it out. Check the Bently manual or search online for the procedure- just don't try to do a half job. Check belt tension is as per the book first as that is the most likely culprit. The filter is inside the resovoir (at the centre) but its easy to buy a new ZF resovior with it already inside- USD$25 or so. But it won't be that unless someone delberately put **** in your system or something is broken.

If you just bought the car the Prev Owner may have tightened the steering box grub screw too much to reduce play... if so, change it before the box dies nad you are up for serious $$$

[whiskychaser]

My power steering doesn't work 100%. It works may be 50% or 30%. Steering is very hard and heavy. My wife can hardly manage the force necessary. It is tough to drive. It seems to get better after half an hour driving but still not good.
Sure it is freezing cold in Boston (minus 10 Celsius) but I haven't had this problem before.
What might be the reason? Is there a filter in the system that can clog and reduce PS?
Any idea? Martin
If power steering doesnt work properly, it can be heavier than having no power steering at all. The steering geometry is designed to work with power assist so if you havent got any you will get some big muscles. Temp shouldnt really have much to do with it. Have you tried to bleed it? - just a matter of leaving it on each full lock for about half a minute. Any fluid loss?- air can get in where fluid comes out. Mine doesnt have a filter in the reservoir but some do. Worth a look. So is replacing the fluid which is probably as old as the car:)

[Barney Paull-Edwards]

The filter is not really effective anyway,as with peddling the car round a track, you need clean fluid. Sounds as though you might also have water in system.

[werminghausen]

Thanks
I changed the ATF in the steering yesterday. I drained at the return hose to the ps pump. The old oil was nasty, black, may be as old as the car. steering seems to be much better now but it isn't as cold at the moment. I will report back as soon as it is minus 10 Celsius. Martin

[werminghausen]

Well it was cold this week in Boston and unfortunately theproblem is still there even with new ATF.
I can't really understand why the steering keeps freezing.

Is it possible that water is in the Steering gearbox which freezes?

Anyone an idea

[Ross]

Have a look at the fluid again, maybe some crap remains.
Take your time though, think of what this will do for the wife's chest.

[Morgenster]

How's the vacuum in the intake of the engine?
The rate with which steering is made easier is dependent on RPM in older cars and dependent on KM/h in newer cars. In either case there's a mechanism that increases or decreases the amount of 'help' the pump gives you and maybe something's stuck there?

[shogun]

http://www.bimmerboard.com/forums/posts/82372


On roadfly is the original post which says in addition to the pic saved above
Author: Yuriy on 2004-07-22


Subject: Repaired my Servotronic today + (2353 views) (4686 thread views)

Message: About 3 months ago, my servotronic started to fail: intermittent shutoffs and then I was stuck with minimum assist until yesterday.

Reflowing the solder, as was expected, didn't do any good, so I decided to work on the circuit itself. Sure enough, after desoldering the two transistors, Emitter-Collector link in both of them either had a ~5MOhm resistance or even was positive on the diode test. In other words, both were BLOWN, BURNED, BUSTED!

I've managed to get the P/N from them and ordered replacements from digi-key.com. Soldered them in and VOILA! :))