Leaking Ps Reservoir - 540i E39

[HardStep]

Hi,
i recently noticed, that the PS reservoir was leaking. As i understand, when changing PS fluid, i need to change the reservoir itsself too, because the filter inside is not serviceable. But do i have to get new hose(s) or is there something else, i can do?
Anyways, can i use like Mobil 1 full synthetic ATF or are there any better choices?
Thanks guys.

[bryan1970]

where is your leak coming from becasue if it looks like it is coming from the cap area that is normal. there is actually a breather hole in the side of the cap and some fluid can find it's way out and look like a leak. the best wat to prevent this is make sure the fluid level isn't too full. and although the filter is in the resivoir i have never changed a resivoir when doing a flush. i'm not saying it is a bad idea but i don't know that is is really something that has to be done.

[sp0rky]

If the hose below looks like it's saturated it may just be the hose. BMW is notorious for having leaky PS hoses on almost every model.

[Eric S.]

Originally posted by HardStep@May 5 2005, 10:41 PM
Hi,
i recently noticed, that the PS reservoir was leaking. As i understand, when changing PS fluid, i need to change the reservoir itsself too, because the filter inside is not serviceable. But do i have to get new hose(s) or is there something else, i can do?
Anyways, can i use like Mobil 1 full synthetic ATF or are there any better choices?
Thanks guys.

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It's usually the hoses coming off of the reservoir and/or the little o-ring on the cap that leak. I just replaced my leaky hoses and it was one of the few repairs I've done on my 540 that went smoothly as planned. So it's easy enough to do. I've not ever read anything regarding replacing the reservoir or worrying about that filter inside. It's probably a very small amount of fluid compared to what is in the rest of the system.

Regarding fluid, Dexron III is required, and I know that the Mobil-1 is approved for that application (as well as most all other ATF apps too). I recommend you use the Mobil-1 ATF. It isn't what I have right now, but I plan to switch to it soon....

[bryan1970]

both the lines off the resivoir are pretty easy to change. theyr pretty straight forward. both go to the pump. the one that is a real pain on a 540 or 750 for that matter is the line from the pump to the sterring box. it is really hard to get the crush rings to stay on becasue it is basically under the exhaust maifold.