Hello All,
I did a search but couldn't find enough info to get clarity on this.
I have a 91 850i, and had it inspected a few months ago. The mechanic found a very faint whine in the power steering, but only while the engine is cold. He said he wouldn't worry about it for now, but that's not really my style.
Since he pointed it out to me, I have been wanting to fix it. I looked underneath the car and found that the underside of the pump is wet. Not a bad leak with a drip, but a faint seep that over time had left a thin coat of fluid coming off of it.
Here are my questions:
1. Bad hoses/connections can cause the leak, could low fluid cause the whine?
2. Does the whine mean the pump is going bad, or could it be attributed to low pump fluid?
I am going to have a closer look at the pump to see if it might be the hoses. I just don't want to replace the hoses if the pump is bad and vice versa.
'91 850i 6spd
Old hoses can cause that too, they swell over the years like old brake hoses. Also old power steering fluid with dirt, moisture inside. Or dirty filters in the system, or in the gear box bottom, pics here of the metal filter on my website, click on the left fixes and go to steering http://twrite.org/shogunnew/topmenu.html
Just yesterday someone on a German forum solved a steering problem, he even changed the power steering pump, did not help, problem was a clogged filter = not enough fluid was flowing.
Here you see the filters in your system http://www.realoem.com/bmw/enUS/part...MW-850Ci&mg=32
And there is no need to replace the pump, there are gasket/seal kits which include the profile gaskets. I have repaired already a lot of these pumps with new gasket kits.
ZF Recommended Steering Systems Flushing Procedure
ZF says: A steering system is an important safety component in a vehicle and must be properly maintained. With this in mind, a steering system must be flushed EVERY TIME a component of the system gets replaced, no matter if the components are new or remanufactured.
Equipment Needed:
- Safety Glasses
- Empty Bottle for contaminated oil
- Screwdriver
- Manufacturers’ Recommended Power Steering Fluid
1- Clean the outside of the oil reservoir and the surrounding area to ensure no dirt or foreign particles get into the oil reservoir.
2- With a screwdriver, loosen the clamp holding the return line connection between the steering gear and the oil reservoir. Disconnect the oil line from the oil reservoir.
3- Insert the end of the return line into an empty bottle and cap the oil reservoir return connection with a plug.
4- While wearing safety glasses, start the engine and fill the oil reservoir with fresh power steering fluid while turning the steering from side to side to purge all oil out of the system. (Use recommended fresh fluid to flush the system.)
5- Turn off the engine and remove oil reservoir from bracket. Flush out debris or particles from reservoir into container. Check oil contamination for metal or foreign particles by filtering the contaminated oil with a coffee filter.
- Fine metal shaving means a normal wear and tear of the power steering pump.
- If metal chips are present, replace power steering pump.
- If black rubber particles are present, the pressure/return line inner lining is disintegrated. Replace the pressure/return line.
6- Check the oil reservoir condition for cracks. If the oil reservoir is cracked, replace the oil reservoir. If reservoir has no cracks, just replace the oil filter. If filter is integrated inside the oil reservoir and cannot be removed for oil filter change, replace entire reservoir.
7- Check the condition of the pressure/return oil line for cracks, soft or sweat spots. If any of these conditions exist, replace lines.
8- Check all banjo bolt connections for blockage. If blocked, clear connections by appropriate method (air hose, fluid, etc.)
9- Reconnect oil reservoir into bracket.
10- Connect return line to oil reservoir.
11- Top off oil reservoir with manufacturers’ recommended fluid.
12- Start engine and turn steering from lock to lock to purge air out of the system.
Caution: Do not hold steering gear from lock to lock for more than 30 second. This could cause the steering system to overheat.
12- Check for oil leakage and top off power steering fluid to recommended level.
The smallest particle can cause the system to leak or even fail. A clean system is a REQUIREMENT for acceptable service life.
Shogun tricks and tips for the E32 series are HERE!
Old is on the Left New is on the Right
Thanks for the replies. It was a quick look prior, and upon going back under there I realized it was the AC compressor that was wet in oil, caused by timing chain tensioner. I just ordered the parts to replace/repair that.
Back to the power steering pump. It is dry, as are all the lines. I still have the very faint whine though, so I want to replace the filter. Is draining the fluid required for a filter change? if not, do you recommend it anyway?
'91 850i 6spd
There some pretty good tutorials out there on changing the fluid but you should get as much out as you can. Turkey Baster will minimize the mess.
Pump the brake pedal till it get's hard, then all the Pentosin is out of the H31 brake bomb and the Pentosin container is full, then use a turkey buster and suck the Pentosin container empty, then you have already about 50% out of the complete system. Then clean the filter at the bottom of the steering gear, so also the fluid inside the steering gear will drain, with that procedure you will have a lot of old fluid out already.
Refill, drive some time, check the fluid again, if still dirty, same procedure as before with the turkey buster.
I would not touch the hydraulic hoses if they are dry.
Shogun tricks and tips for the E32 series are HERE!
Thanks Shogun... Great direction. I'll be doing it this weekend. I agree about the lines, I was hesitant to agitate dry lines.
I found the pictures of the steering gear filter on your site. Big help.
Once fluid has removed/drained, strainer cleaned, filter replaced, do I need to bleed the system when filling?
'91 850i 6spd
no need, that is self bleeding, see in my post above item 12
12- Start engine and turn steering from lock to lock to purge air out of the system. Caution: Do not hold steering gear from lock to lock for more than 30 second. This could cause the steering system to overheat.
Shogun tricks and tips for the E32 series are HERE!
Awesome! Super helpful per usual.
'91 850i 6spd
Ok- I found access to it, however I do not see the servotronic torque converter. Is it possible I don't have that?
Mine looks like this:
http://www.realoem.com/bmw/enUS/show...diagId=32_0294
NOT this:
http://www.realoem.com/bmw/enUS/show...diagId=32_0287
And if that's the case, is there another point at which I can drain the remaining fluid?
'91 850i 6spd
Hex drain plug (use hex Allen wrench) at the bottom of power steering pump.
Bert
91 850i-A
1972 3.5 CSi (L-jet, Getrag 265 5 speed)
1988 ///M6
2021 X3 M40i
The back to back BIG COUPE” duo
Thanks. Drained it tonight. There was a blue sealant on the threads. Do you know what that is?
'91 850i 6spd
Blue Loctite on drain plug. Use liberally.
Replace the filter in the small cartridge on the front of the oil pan too, most people ignore this and it makes a big difference. #13 on this diagram
http://www.realoem.com/bmw/enUS/show...diagId=32_0299
As for your leak.... the pump is the lowest part of the system, so it isnt necessarily the origin, but it is a good place to start. If you undo the banjo bolts connecting the hoses to it, replace the crush washers with new ones - do not re-use these. You can order assorted sets of these on Amazon for minimal cost.
As for the hoses themselves... there are only 2 true "pressure" hoses in the system, the rest can be rebuilt with basic tools and clamps. Don't get too carried away, there is a lot of them... but it is usually the non pressure hoses that start to leak. Take your time to track down the culprit(s)
- - - Updated - - -
...and Shogun is telling you to not hold the steering WHEEL in full lock (turned all the way left/right) for too long when bleeding the air
standard procedure for E36 M3 drivers, here some instructions
http://www.gvc-bmwcca.org/_download/...eeringHose.pdf
https://photobucket.com/gallery/user...MzA4OQ==/?ref=
You should also try to get into the habit of getting hose clamps with rolled edges, instead of the flat band style. It will help in avoiding deformation of hoses.
https://photos.smugmug.com/MotoIQ/Te...P1050066-M.jpg
https://photobucket.com/gallery/user...MjcuanBn/?ref=
https://photobucket.com/gallery/user...MzAuanBn/?ref=
https://photobucket.com/gallery/user...NDUuanBn/?ref=
https://photobucket.com/gallery/user...MzguanBn/?ref=
http://farm4.static.flickr.com/3367/...b0e80cde_b.jpg
https://photobucket.com/gallery/user...ZXMuanBn/?ref=
did that on my E36 M3 too http://e32b12.blogspot.com/search/label/M3
and also on my E32 750 which uses the same power steering pump as some E31, feed and return lines do not have high pressure
Last edited by shogun; 03-27-2019 at 10:02 AM.
Shogun tricks and tips for the E32 series are HERE!
Thanks Cartoonz- good recommendation! I just ordered it, so I'll be replacing fluid with 11S and changing the cartridge filter and pentosin container filter.
Turns out there were no leaks, so not going to mess with any of the lines. Hopefully, the above sorts out the faint whine I had.
'91 850i 6spd
While you CAN do this, you may want to rethink doing it at this point.
Here's why...
CHF 7s is mineral based, 11s is synthetic. This is why you CANNOT mix them.
Yes, you CAN use the 11s but you must very thoroughly flush the entire system of the original 7s.
This involves several complete system flushes to accomplish.
Some say that switching from mineral to synthetic reacts with seals/hoses somehow and leaks may happen where there were none before, but I'm not sure what to think of that theory.
So, unless you bought a case of the CHF11s, you might consider sticking with what BMW intended... and yes, it IS available, Febi makes it.
I've done this switch on a couple of cars, but there really is no advantage to doing it. The 11s really isn't magically better than the 7s in any perceivable fashion.
'91 Dinan 860 Stage III (new 6L engine)
'91 Dinan 850 TT stage III (brand new engine) 21st Century Tech meets 18th Century Dinan...
'91 850i 6sp (mint) (sold)
'90 Dinan 750iL TT stage III (Guido - The Beast)
'94 850 CSi The Detroit Auto Show car (restored to factory perfect) (sold)
'96 850Ci, The George Carlin car
''73 3.0 csi, '08 535i, '03 X5 4.6is
...and a few other non BMW cars
sorry , a bit of topic.... but why does the pressure line for the ASC+T go's ( needless ? ) all around the engine ??? just to have a suitable place for the filter … ?? It involves 2 flex hoses… to reduce the "pulse" pressure from the pump ?? i just wonder....
Probably has a different reason, maybe just available space. I was wondering about this line around the engine last year when I had to replace it because of leaks. My 89 750 does not have ASC+T. On my car that line around the engine is for the rear self leveling. From power steering pump on left side engine bay 1 x around the engine oil pan to the next connection point left side http://www.realoem.com/bmw/enUS/show...diagId=33_1553 11 Feed line 37131137458 ENDED/NLA. As that line is a high pressure line, I sent it to a shop here in Japan which replaced the high pressure hydraulic hoses and recrimped them. In that area 130 bar! Checked the original hoses of that line, it is designed for 180 bar bursting pressure.
The shop now installed for me new hoses suitable for max 220 bar.
Shogun tricks and tips for the E32 series are HERE!
Shogun tricks and tips for the E32 series are HERE!
use the Febi M 6162, or 06162 (same thing), CHF 7.1
You can actually get this from your local NAPA store for a bit over $7 a bottle right now...
Last edited by cartoonz; 04-07-2019 at 04:41 PM.
'91 Dinan 860 Stage III (new 6L engine)
'91 Dinan 850 TT stage III (brand new engine) 21st Century Tech meets 18th Century Dinan...
'91 850i 6sp (mint) (sold)
'90 Dinan 750iL TT stage III (Guido - The Beast)
'94 850 CSi The Detroit Auto Show car (restored to factory perfect) (sold)
'96 850Ci, The George Carlin car
''73 3.0 csi, '08 535i, '03 X5 4.6is
...and a few other non BMW cars
Cartoonz, odd question, when you use the blue loc-tite on the drain plug, is there any special technique or just liberally coat the threads. I usually drain the system from the plug, but of course a friend's car seems to always want to leak from that thread after we did a drain and fill.
Does anyone have a replacement part number for that plug?
Regards,
Brian
Cave Creek, AZ
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