40k miles ago, I replaced the power steering pump with a reman.
Over the last 6 months (5k miles or so) I've replaced all 4 power steering hoses.
I developed a leak at the reservoir, so I replaced those 2 hoses. Upon replacing those hoses, I noticed that one of the box hoses was leaking where it was crimped near the cooler. I patched that up with some rtv and it held for a while, but I soon decided to replace the 2 box hoses as well.
I replaced the 2 box hoses and noticed a leak at the cooler. I realized that I did not put on an o-ring, and had to drive on it (refilling once a day) while I waited for a new o-ring to arrive in the mail. The whole time, the steering made that whining sound like it does when it's low on fluid. So once the o-ring situation was resolved, i could still hear that steering whine noise. A day or so later, I noticed another leak. It would leave coin sized spots in the driveway. This time it was coming from a power steering box connection. It was a slow leak and I had already maxed out my 'working on the car is fun' meter for the quarter, so I ignored it and kept adding fluid periodically.
One day, I went to add fluid and noticed that it was pretty low. The noise went from a whine to a grind. So I topped it off. The next morning I started the car and it sounded a bit different than usual. I thought 'hmm' but I drove to work. I went to leave work at lunch time and started the car, but this time I heard a slight belt squeal. My negligence had lead to the power steering pump failing and ripping itself from the motor. Both brackets had broken, and the long mounting bolt had bent.
As I was replacing the destroyed reman pump with a brand new LUK, I decided to look at the power steering box leak. Turns out, I had installed the wrong crush washer on one of the banjo bolts. The washer I used was way too big and it was not making a good seal.
Leaks are gone, but I have noticed a few things.
When I re-filled the system, it only took maybe 3/4 of a quart. I imagine some was leftover in the box, but that much?
The steering is still making a noise. It's not a real loud noise, but somewhere just over a feeling in the steering wheel. The noise is present not so much when I turn left, but more so when I turn right. -I thought I bled it correctly by adding fluid, turning the wheel all the way in both directions, bleed, and repeat until full.
Is the noise normal? Do I have debris in the system? Should I rinse out the reservoir with gasoline or get a new one? Is my box bad? Could I have bad tie rod ends? Is my pulley not lined up correctly causing the noise to be made by the belt? I can record audio if that would help.
2003 540i/6
The pulley shouldn't be mis-aligned. It's alignment is set by the 2 tabs (that broke) bolted to the upper oil pan.
The long top threaded bolt is just for additional support, not alignment.
If you do flush the resevoir you can remove the torx (?) screw inside to free the plastic screen (it won't come out of the resevoir) so you can flush out anything that is under the screen.
3/4 of a quart sounds about right, the steering box and the cooling coils still had fluid left in them.
Your pump has a bunch of vanes in it that can be damaged if the pump runs dry.
Good luck.
Last edited by JimLev; 09-01-2017 at 09:41 AM. Reason: fix typos
Suggestion: The filter built in to the reservoir is more than likely clogged and restricting flow. Hence the noise from the system. Most people just replace the reservoir than try to flush the filter as it is a PITA to get it right and not worth the few dollars saved. Replace it and replace the clamps that hold the hoses at the bottom of the unit with one time use ones. I would flush out most of the existing fluid from the system as possible to ensure it is clean.
Good luck
Helpful?
Last edited by StephenVA; 09-01-2017 at 09:44 AM.
Current Garage Highlights
2003 525iT TiSilver
2002 M5 TiSilver
1998 528i KASCHMIRBEIGE METALLIC (301) (Goldie)
Former Garage Highlights
2005 X5 4.8is
2004 325iTs (2x)
1973 Pantera L
1971 Dodge Dart Swinger "Lite Package"
1970 Dodge Challenger T/A 340 Six Pack Alpine White
1970 Dodge Challenger T/A 340 Six Pack GoManGo Green
1969 Road Runner 383
1968 Barracuda Formula S 340 Sea Foam Green
Thanks for the help. I just ordered a new reservoir.
-side note:
I've ordered a few parts from RM European recently and they have shipped everything same day.
2003 540i/6
It's a 5 min job to unscrew the screen strainer and clean it once to have the resevoir out of the car.
Waters, check it out when you have the old one out, it can be your spare.
I think I'll do that. Thanks.
2003 540i/6
I swapped out the reservoir today. The steering is still making a noise when turning right though. Where does the noise come from? Does it come from the pump or does it come from the box? Is it possible that there's a pocket of air trapped in the box that just won't free itself?
I read up a bit more on bleeding the system today. Some people say to turn the wheel all the way and turn the car off. Let the car rest for 20 minutes or so and then turn the other way and do the same. I think I'll try that tonight.
Anyway, here's the old filter. It looks dirty, but doesn't seem to be dirty enough to really clog things up. My guess is that this is original to the car. I remember when I first got the car, the fluid looked like coffee with cream.
filter.jpg
2003 540i/6
When the noise happens while turning the wheel to the other direction but not so much when the other, is a sign that you have air inside the steering box. Recovery from this situation is difficult, since the pump pressure somehow isn't enough to clear the air bubbles from the box at least in a straightforward manner. I've always warned everyone to not turn the wheel when flushing the fluid and the system is empty due to easily ending up with this problem.
That actually kinda makes me feel a little better. Any suggestions on bleeding out the air?
2003 540i/6
When I landed once in the same situation, I kept trying to bleed it with the normal method (turning the wheel back and forth from one extreme end to the other) and it got somewhat better over time but the noise was never completely gone. The other tricks are having the car tilted or in up/downhill while doing it and the pump condition and what fluid is being used (viscosity) may have some impact on success as well. Repair shops may have a higher pressure hydraulic pump to run the fluid through the steering box to get the air out.
If anyone has a magic trick for this, I would be interested to hear it too.
Last edited by vinyldude; 09-07-2017 at 06:39 PM.
I think I found a solution. I just ordered a Mityvac MV8000 Automotive Test and Bleeding Kit. It'll be here on Wednesday, but I probably won't be able to get to it for a week or so. The car is currently on jackstands while I have slowly been fixing rust on the rear quarter panel around the wheel well. Pitting sucks.
Here's a video about it.
I'll post my results after the bleed.
2003 540i/6
Sort of looks like my Mityvac pump. Is it all plastic? If so don't drop it, it'll break.
Your PS pump has a drain valve on the bottom, never had a problem getting air out, just drain and refill a few time and you'll replace 95% of the old fluid.
DSCN8673.JPG
Last edited by JimLev; 09-19-2017 at 01:24 AM.
I finally got around to using the hand pump. It's a really horrible method if you have a lot of air in the system. I pumped it up to 10 inches of vacuum and after about 15 seconds the vacuum is depleted. I couldn't even get it up to 15. So I did the hand pumping and lock to lock for about 20 minutes on Monday and then for about a half hour today. However, if I plug the end of the pump tube with my finger, it doesn't lose any vacuum. This at least tells me that it's working. I got frustrated with hand pumping the thing and turning the wheel, so I connected the reservoir to my oil extraction pump and pumped it about 4-5 times. That created a much better vacuum that actually held. Unfortunately I have no idea how much vacuum was applied.
The noise is mostly gone and when I open the reservoir, I can see tiny tiny little bubbles flowing out. I think I'll have to go through this a few more times to completely purge the system of air, but at least I'm getting somewhere.
2003 540i/6
Thank you for reporting back on the success of this method. It sounds like it is working. Did the pump come with a working adapter to connect to the PS fluid reservoir or how did you do it?
I may have to try this on my X3, which has some PS noise that does not go away with the lock to lock method.
It did not come with an adapter for the reservoir. You can get one for like $15 though. It's like a bung with a hose fitting on it.
I had an old reservoir so I just drilled a hole in the cap and rigged up one of the plastic tube fittings that came with the pump kit. The kit is pretty cool, you can use it to bleed brakes too.
2003 540i/6
Hmmm. I'm not so sure about the bleeding. From your OP condition + 'confessed abuse' stories, I suspect easily the box might still have some sludge in it. What kind of ATF are you putting in?
When I put the M5 box in, it was dry and had probably gotten some condensation in it from lying open for a while waiting to go in, junkyard box of unknown provenance etc. etc. I had pretty bad noises regularly, until I did a heavy repeated flush routine.
At no point did it really take more fluid so I am pretty sure it's not a bleed / air issue, but more of a cleaning gunk issue. For the first few flushes, it continued to drain out black ATF with stink to it... As a result, I'm on record as being a big proponent of using some nice gucci syn in the box and repeated flushes.
I also put an aftermarket magnefine filter inline with the return since the factory filter might leave something to be desired and I've had great luck with those in previous cars.
Now you sorta have been doing flushes already with the pump change, but my suggestion would be:
- splash a small amount of some commercial 'PS flush' stuff (aka Lucas or whatever from the snake-oil shelf at the FLAPS) into the reservoir, run it for a short period (maybe just short drive around the block, or rotate steering with wheels off ground), let it sit, then drain.
- refill with a good syn ATF...albeit perhaps something cheaper - I used Castrol Transmax ATF+4 for my disposable flushes because I found some on sale but its still all syn
- run it for a few days of driving then drain and inspect (sniff! yuck!)
- repeat until you can run a longer change interval and the stuff coming out looks like new
- then refill with the ATF of your choice. I'm sure the transmax is great, but I think I've got redline or M1 ATF in there now. all of those are way overspec'd for the job but contain lots of gucci additives that work the magic on cleaning stuff up and conditioning seals.
Doing the above (and the magnefine filter) turned a groany M5 box - that I was nearly convinced (and very definitely told by mechanics) was junk and needed to be replaced - totally silent, and that was years and many 10k's of miles ago.
Oh and yeah, couple last notes- yes a regular drain takes less than a quart as Jim says... and... personally I think buying a new reservoir is semi-pointless (after having done it myself so not pointing fingers) as long as there's not something else wrong with it. The OE one can easily be washed out to like new status...
2003 M3CicM6 TiAg
2002 540iT Sport Vortech S/C 6MT LSD TiAg
2008 Audi A3 2.0T DSG (the daily beater)
2014 BMW X1 xDrive28i (wifemobile)
Former:
1985 MB Euro graymarket 300SL
1995.5 Audi S6 Avant (utility/winter billetturbobattlewagen)
Last year when it was leaking really bad I was saturating the landscape with Valvoline Max Life. That stuff smells absolutely terrible, btw. Then I used a little gas station store brand atf when it ran dry before replacing the pump. (maybe half quart). When I replaced the pump, I filled it with Castrol Transmax Import/multi vehicle.
After seeing all those tiny bubbles, I'm convinced it's air, and from what I can see, the fluid in the reservoir still looks brand new. I think the air is getting agitated in the box and creating super tiny bubbles. There seems to be a steady flow of them. I may still do a flush, but I think this weekend, I'm going to let the car sit for a day and hopefully the air will re-collect itself. I'll then attach the pump with the motor off and apply a vacuum. (maybe turn the wheels. I will then start the motor and hopefully, it'll suck the air out in one go before it has a chance to get agitated.
I'll shoot a video of the fluid flow tonight so you can get a visual of what it's doing.
2003 540i/6
OK then your constant refill has basically given it the flush treatment already. Could the bubbles be getting introduced by a leak at the suction side of the pump? Aka pump is sucking just a tiny bit of air in and 'aerating' the fluid?
2003 M3CicM6 TiAg
2002 540iT Sport Vortech S/C 6MT LSD TiAg
2008 Audi A3 2.0T DSG (the daily beater)
2014 BMW X1 xDrive28i (wifemobile)
Former:
1985 MB Euro graymarket 300SL
1995.5 Audi S6 Avant (utility/winter billetturbobattlewagen)
Whoa! Let's not go down that road yet.
2003 540i/6
Here's the video. Dammit, GG, why'd you have to plant air leak in my mind?
The bubbles come out so slowly, it makes me think you could be correct, but also makes me think the air is being really stubborn. I'm leaning toward the latter, because I'm being really stubborn.
Also, listen to how smooth that motor sounds! Smooth like an old tractor.
2003 540i/6
At least if the power steering noise comes back being worse again, I think GG's theories make sense. But you would think you would have a visible fluid leak somewhere in that case.
The crummy thing is that air is thinner so it could still be drawn in without any signs of a leak. What really sucks is the vacuum pump could essentially make GG's scenario much worse.
2003 540i/6
When I had bubbles like that it was a leak on the suction hose. Well actually way worse than that, bubbles were flowing so much the fluid started looking milky. Mine did actual leak fluid but hardly, if I drove daily I might not even get a drip, but if I let it sit for weeks I'd start to get a small puddle.
You not being able to hold a vacuum (assuming your cap was sealed well) plus the bubbles really seems like a leak on the suction side.
Sent from my Pixel XL using Tapatalk
Everything in the power steering system is new with the exception of the box. I can't imagine where a leak would be.
I tried bleeding it again. I figured out why my hand pump wasn't working correctly. I didn't have the breather vent in the reservoir plugged up properly. (I am using my old reservoir cap with a fitting inserted into it)
I was at last able to get the hand pump to hold a vacuum. I tried 20 lock to lock with the engine off, and 20 with the engine running. Still seems to make the same groaning noises. They're subtle, but still annoying.
Also, why get the m5 box? Isn't it the same as the 540, but with servo assistance, or is it also geared differently? If it's geared differently, does it provide easier steering without the servo assist? Do you need to do any programming to make it work with the 540?
Last edited by waters17; 09-30-2017 at 07:06 PM. Reason: autocorrect fixes
2003 540i/6
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