E34 535i: Oil leak at pipe conencting steering pump to steering tank

[Jazz_89]

Hello guys,

I own a 89' E34 535i and this is my first thread. The pipe that connects the steering fluid pump with the steering fluid tank is leaking oil. Not rapidly, but every day a few drops The one leakage source is at the connection to the tank and there is a lower leakage source at the metal connection where the plastic pipe is fixed. Do I need to replace the whole part (costs 115 Euros) or is it possible to install a new plastic pipe from a normal dealer and fix it on the metal connection? :/

Thanks alot!

[shogun]

I have replaced those hoses with oil/fuel hoses, I have posted some pics here from my E36 M3, you could do it similar. Cut off the crimped sleeces and replaced the old hoses with hydraulic hose with hose clamps. This works only on low pressure hydraulic lines
http://njbmwcca.org/wp/wp-content/up..._HOSE_Rev0.pdf

http://www.bimmerboard.com/forums/posts/1193648

[632 Regal]

The metal connection is the problem, It is a high pressure hydraulic fitting. In a normal application you could have a hose made but in this particular scenario I think you will need to get the real part because of the tight bends in the rubber hose.

[shogun]

That is not a high pressure side, On one side it is a hydraulic fitting because it has to be bolted onto the power steering pump with the banjo bolt, on the power steering reservoir it is just a hose clamp.
Feed and return line from/to reservoir are not high pressure lines.
I did exactly that also on my E32 750 as well as the E36 M3 with a hose, here more pics from my M3 http://e32b12.blogspot.jp/2013/03/e3...-oil-leak.html
On my 750 the hose also has a tight bend, I made the bend with the new hose a bit wider to avoid kinking.
The hose I used has following spec: fuel-gasoline-diesel-oil hose, inside NBR, enforced structure, outside CR, temperature resistant -40C° to +100C°, pressure resistant up to 20 bar, very flexible.

[Jazz_89]

Thank you both for the useful advice and the links.
Now the problem got a bit worse, because the other pipe from at the reservoir is also leaking. I must replace both. I found pipes+reservoir from an E34 525tds. Do you think they will fit on the 535i?

[632 Regal]

Thank you both for the useful advice and the links.
Now the problem got a bit worse, because the other pipe from at the reservoir is also leaking. I must replace both. I found pipes+reservoir from an E34 525tds. Do you think they will fit on the 535i?

Jazz, check the realoem site: http://www.realoem.com/bmw/enUS/select find the hose you need and copy the part #, then search that number here again: http://www.realoem.com/bmw/enUS/select That will cross reference all the cars that it will fit.

[Jazz_89]

This website is really awesome. Thanks
I cross checked the parts and it says that the one pipe I ordered only fits to the 525tds... I hope that only the length is the difference.

[632 Regal]

This website is really awesome. Thanks
I cross checked the parts and it says that the one pipe I ordered only fits to the 525tds... I hope that only the length is the difference.

Let us know.

[Jazz_89]

Ok, so what you need is:

-Hose that connects tank to pump (large)
-Hose that connects tank to oil cooling system (small)
-ATF oil
-Pipe clamps
-22mm wrench for the lower plug
-13mm wrench to remove the tank
-Screwdrivers to set the clamps
-Oil pan
-A new tank (but not necessary)

Here are the parts:


You start by putting the pan under the steering oil pump and remove the plug that connects the hose from the tank to the pipe (use the 22' wrench) Let the oil drain in the pan:

[Jazz_89]

Remove the generator air cooling duct for better access. Then, use the 13mm wrench to loosen the oil steering tank from the chassis.
Cut the thinner hose, for the connection tank-cooling system carefully, until it reaches a suitable length and connect it to the tank with a clamp. I used some oil in order to slide the hose on the tank. Connect the other end only later, after you are finished with the thick pipe.
Here is the thinner hose connected to the steering oil cooling system:


Adjusting the thicker hose for the steering oil pipe is trickier. You have to bolt the hose a few turns on the pump and see if the length is suitable for connecting it to the tank. It is important to remember that with a hose cut too short, you will not be a able to reach the tank and with a hose too long, the metal connecting part will be under constant tension because of the deformation at the point where leaks usually occur. Also, once you slide the hose on the tank it will be almost impossible to remove it without damaging it it.
Here is the thicker hose connected to the oil steering pump:


After you are finished with this, you can connect the other end of the thinner hose to the cooling system and you can tighten the tank again on the chassis.
Carefully tighten the oil plug on the pipe and don't forget the metal ring attached to it. Add some steering oil in the tank, screw the cover of the tank on a few turns, and let the engine run for 10 seconds. You should notice, that the level in the tank is lower now and that the color turn darker because the new oil is mixed with the old oil that could not drain completely out of the system. Add a little bit more oil and repeat the procedure while also turning the steering wheel a few times gently, until the level is ok. I heard some noises on the beginning but they quickly disappeared. At the end, check for leaks.

This is the first time I fix anything on the car, so there might be things that I missed or possibly did incorrectly. The advice should serve as a guide for fixing this, but if you are not 100% sure, consider asking a professional.