Help: power steering pressure hose keeps coming loose

Hi all,

I'm having a lot of problems with my power steering system on my 03 330i. The original pump went bad a month or so ago so I swapped it for another LF20 from oembimmerparts, along with a new reservoir and fluid cooling hose. A couple weeks later I started having no P/S on start, had to shut off and start again to get it back - the fluid was leaking out of the pump overnight.

Brought it to an Indy shop last Friday because I had no time to look at it - their diagnosis is I forgot to replace the Oring on the pressure line. They replace it and charge me a lot of money to do so. Fine, at least it works - NOT!

Still had no start a couple times since then and yesterday went on a "spirited" drive with lots of high RPM and eventually noticed that I'd lost ALL of my ATF/PS fluid. Took it into a friends shop and the line was pretty loose and the Oring all chewed up - we replaced it and replenished the fluid but I'm waiting for it to come loose again.

Problem is, the pressure line doesn't screw all the way down - it fits but it's tight before the nut hits the pump. I don't think this is how it was on the old pump. Did they change the design? I know some come with LF30 but both my old and new pumps are LF20, just the pressure hose doesn't screw down all the way into the new one. Maybe that's fine, but I'm suspicious that that's why I'm having problems with it.

Thanks in advance for any insight.

This is the pump I bought - http://www.oembimmerparts.com/mobile...lt.aspx#P40045

Just realized that it's not OEM. Ugh. Supposedly it's the same and is re-engineered with a better shaft, but what good is that if the pressure hose doesn't even fit. FWIW the two pumps looked identical.

Just confirming that the pressure hose is actually supposed to bolt all the way down before I send the pump back for OEM and do the job again....

If memory serves, there's a different line for the different pumps.

See realoem.com and see if you can figure out what's going on, but I'm pretty sure I recall having read that here...and that might be all it is.

Hope so!

Hey dmax,

Thanks for the reply - there's definitely a different line for the LF20 and LF30, but I didn't change between the two - kept with the lf20 because I'd read that steering is heavier with it and the steering feel is one of my favorite parts about the car!

If the line comes loose again, there's nothing to do but return the pump for OEM. Pretty strange that Atlantic Enterprises would make an LF20 identical except for the pressure line bolt in point. It's tight now and seems to be holding up but the last couple times it came loose within a week.

There's always blue loctite. If it's sealed/not leaking, loctite should do the trick...and also, you might check the torque specs on it...and remember with loctite, you'd need less torque as wet, it's a lubricant.

GL...sorry I just skimmed and offered that hose suggestion!

I bought a pump from a local parts store a while back. I don't remember the brand but i had to use the fitting off the stock pump in the new one. It would snug down but not lock the hose in tight. Im betting you can use the stock fitting in the new pump and be on your way.

Sent from my DROIDX using Bimmer App

Originally Posted by dmax

If memory serves, there's a different line for the different pumps.

See realoem.com and see if you can figure out what's going on, but I'm pretty sure I recall having read that here...and that might be all it is.

Hope so!

Dmax is right on the different hoses


sent from my dahc-6900 using Bimmer App

Originally Posted by dmax

There's always blue loctite. If it's sealed/not leaking, loctite should do the trick...and also, you might check the torque specs on it...and remember with loctite, you'd need less torque as wet, it's a lubricant.

GL...sorry I just skimmed and offered that hose suggestion!

It's definitely sealed when it stays tight. Good idea on the loctite, definitely using that if it comes loose again over buying an OEM LF20 for +$140 that will probably just break again. Might as well give the supposed improved AE pump a chance. Fingers crossed but it seems to be holding well - would love to not drain yet another quart of ATF!

Originally Posted by willsbma

I bought a pump from a local parts store a while back. I don't remember the brand but i had to use the fitting off the stock pump in the new one. It would snug down but not lock the hose in tight. Im betting you can use the stock fitting in the new pump and be on your way.

Sent from my DROIDX using Bimmer App

I'm not sure what you mean by fitting - as far as I could tell, the pressure hose just bolts into a thread on the pump and is supposed to just lock in there. I had to reuse the mounting bracket, but other than that I didn't see any removable parts. Did you have an LF30?

Originally Posted by repoman89

I'm not sure what you mean by fitting - as far as I could tell, the pressure hose just bolts into a thread on the pump and is supposed to just lock in there. I had to reuse the mounting bracket, but other than that I didn't see any removable parts. Did you have an LF30?

The fitting I am referring to is a bushing. The bushing that came on my replacement pump wasn't the correct size. I was able to tighten it, but it would not lock the hose into place. I swapped the bushing from my old PS pump into the replacement and I was able to tighten the hose properly. I am betting this is/was your problem because you would be able to make it very tight, but fluid would leak out everywhere.

Originally Posted by willsbma

The fitting I am referring to is a bushing. The bushing that came on my replacement pump wasn't the correct size. I was able to tighten it, but it would not lock the hose into place. I swapped the bushing from my old PS pump into the replacement and I was able to tighten the hose properly. I am betting this is/was your problem because you would be able to make it very tight, but fluid would leak out everywhere.

Could be - unfortunately I trashed my old PS pump The bushing you're talking about also didn't seem to be removable on either of my pumps.

My problem is a little different though, I can make it very tight and it's "locked" - won't go any tighter but the tightening nut is not up against the pump, and it also doesn't leak (good seal). But, it seems to loosen slightly over time. I've been driving for over a week now with it loose enough that the fluid drains from the pump overnight and requires two starts in the morning to suck some back down from the reservoir and have working P/S. Luckily, that is apparently a really small amount because the fluid level doesn't seem to be going down.

My jacks/stands are 50 miles away at my dad's so I need to find time to drive all that way to drain the fluid yet again and put some Loctite on the threads

Originally Posted by repoman89

This is the pump I bought - http://www.oembimmerparts.com/mobile...lt.aspx#P40045

Just realized that it's not OEM. Ugh. Supposedly it's the same and is re-engineered with a better shaft, but what good is that if the pressure hose doesn't even fit. FWIW the two pumps looked identical.

Just confirming that the pressure hose is actually supposed to bolt all the way down before I send the pump back for OEM and do the job again....

If you started with an L30 and went to an L20 then you may have hose connection issues. Watch this. Also, the L20 is the one prone to breaking which is why the L30 came out.