159 Power steering noise

[gerwil]

So I think I have the answer to the power steering noise issue with the 159 and maybe others. The reservoir has a plastic white mesh tubular filter inside the sealed container. This becomes dislodged and 'floats around' inside the reservoir allowing the incoming fluid to agitate making lots of bubbles which reduces viscosity and causes the pump to start to whine.
I read some guys end up buying new reservoirs and even new pumps. But the filter is easy to reattach once you know how.
If your return line on the outside of the reservoir (small pipe) has a brass sleeve sticking out, read on. If you shine a bright light inside and put the filter back in it will light up the inside a bit so you can see where it goes. Bit hard to explain but it slides down some shoulders on each side of the return hole. It's a bit fiddley but once it's slid down, push the brass tube back in, which locks the filter in place. Not sure why the brass tube came out in the first place, maybe the hose clamp became too loose.
I also flushed out the factory clear liquid and put in the green LDAS synthetic fluid even though some shops do not list it. Been a few days now and all good. 

Cheers

[bm282]

Wish I had seen your post earlier - I had the same problem on my 159 2.4D where I noticed it had started foaming in the reservoir when I checked a noise coming from the power steering. It was filled with red Dex III. At that point, the filter was still attached inside the reservoir. I ordered a replacement reservoir to make the change as I had read Bazz's comments. Took a while to arrive and before it did, one day I had checked the reservoir and it had the filter floating around inside and the oil was now very brown - I guess the crap in the filter had now washed out into the oil. When I took the reservoir off, I did see the bronze liners on both pipe connectors were both protruding out where the hoses attach. Unfortunately, I tapped them both back in before realising they were how the filter was held in place. Can't figure out how to push it back out to put the filter in place. I flushed the dirty oil out of the system and refitted the reservoir thinking at least I would have clean oil until the new reservoir arrived. But on refilling, it now REALLY foamed and I started getting noises from the pump. Fortunately, the new reservoir arrived the next day - fitted it. Foaming all gone, pump now quiet and power steering good. Did not change from red to green as the recent advice is if there is no problem with red, don't change if your car has reasonable kms/ age (mine is 143k km). So now power steering is all good. Still, would have been nice to be able to fix the old reservoir and see if the problem went away. But certainly a new reservoir fixed the problem.

[bazzbazz]

Unfortunately the usual case is that if you reattach the filter it comes off again sometime in the future.

Time will tell, and hopefully this is one case where the norm is defied.