Hydraulic Steering Conversion (for M54 engines)

Yep that's what I've done to it now. I've taped it flat against the back of the EPS module, but I have a slight concern with it being at a right angle and the corner of the tube it sits within wearing the ribbon cable - guess I'll cross that bridge if I get to it!

Also made a little blanking plate for the column housing where the motor would otherwise go. Not sure it was necessary but I thought the potential for dust and dirt accumulation in the worm gear housing was worth avoiding - can see a build up impacting steering feel if it starts to grind or clog up between the column shaft and the housing.

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Then mounted the column back into the car and have just fastened the EPS module to the back of the dashboard structure/frame(?) with some cable ties and foam padding. Nice and sturdy and no more bulky EPS motor - saves 4.01kg roughly according to my scales. And as you mentioned, the Sport mode button still works as expected which is fantastic!

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(Photo taken from pedal-box area of footwell, looking back and up behind the dashboard)

Now just to get the light coded out, but that's it (and maybe a good four wheel alignment haha); a complete steering conversion. What's great about this is, since the EPS motor worm gear hasn't been cut off, this is an entirely reversible procedure for anyone wanting normal electric steering again.
 
I will be embarking on this mod in the summer and have a question to ask....if the eps module is retained to keep the sport button and whatever else it does, will the module not still be liable for the same problems that usual befall the eps modules on a standard Z4 when they go bad... no communication with scan tools, sport button malfunction etc ?
I'm thinking if I go to all the trouble of the conversion yet the car may still have eps module problems after what is the point? the module will still have to be sent off for repair, am I just being dumb?
as for intermediate shaft I have already finished mine I copied the instructions given by Patrik Ertinger on Facebook which uses the standard E85 shaft and readily available parts from the E46, basically after removing the lower uj from the E85 shaft you will be left with a shaft with an oblong end... then drill the 2 rivets out of the original E46 joint separating the uj from the rubber doughnut part, keep the uj... then a joint complete with rubber doughnut for a LHD E46 is needed this has an oblong shape socket on the top, again drill the same 2 rivets out and keep the top half of the doughnut with the oblong fitting then bolt all 3 parts together ..E85 shaft oblong end into the oblong socket on the LHD doughnut then bolt the original E46 uj to the lower part of the LHD doughnut, its easier than it sounds.... the LHD joint I used was ebay item 202226640777 if you look at the top of it you will see the oblong shape in the mount that is where the E85 shaft goes the other side has a splined hole this is the bit you remove by drilling the rivets out then you bolt the original E46 uj to this. pictures of the one the facebook poster did are very good and show what the end result will look like
 
I'm not
xantiaman said:
I will be embarking on this mod in the summer and have a question to ask....if the eps module is retained to keep the sport button and whatever else it does, will the module not still be liable for the same problems that usual befall the eps modules on a standard Z4 when they go bad... no communication with scan tools, sport button malfunction etc ?
I'm thinking if I go to all the trouble of the conversion yet the car may still have eps module problems after what is the point? the module will still have to be sent off for repair, am I just being dumb?
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My instinct would be to say that yeah it could still run into issues down the line, as even without the motor in place it's still an operational module and so things could go wrong; the chances of that though? I feel comfortable with the amount of work I've done vs the possibility it goes wrong - I wouldn't write off the conversion for fear it might fault in the future. Fully unresponsive modules... tough luck I guess? If it's just having an issue with certain aspects of it's operation then maybe not so much.

Once I'd removed the motor, it put an EPS warning light on the dashboard so I had this coded out by ZedCoding - I think he used one of the INPA/ISTA programs so I imagine this can be done by anyone competent with that stuff (which I'm not lol).

If you were to run into errors post-conversion, I would be thinking to look into the possibilities of having the entire EPS module coded out (since you no longer have EPS), and then look to have the effects of the sport button mapped elsewhere - I think it's only change is to throttle response anyway, since the weighted steering comes from the motor which is removed in a conversion. The only other consideration I would have without thinking much more on it is for the steering angle sensor; however this works, if it's tied into the EPS module or has the data stored elsewhere, maybe it can also be coded out/elsewhere to remain functional? But yeah, the ECU being non-communicative, that sounds like luck of the draw
 
Hi all I realise this is an old thread but I am shortly going to be doing this conversion on a M54 engined z , I have all the parts listed from a donor E46 but I have just noticed that the pas pump is the LF30 so I will need to source the LF20 plus its brackets, my question...are the hoses the same for the LF20 as all the hoses I have are for the LF30 thank you
 
Yeah so this is something I'm not quite so sure about anymore, since the time I did the write-up. I've seen others who have mounted an LF30 pump to the M54 block, so it must be possible. From my own testing, I could not get an LF30 pump to fit while still having the pulley be in line with the rest of the pulleys on the auxiliary belt - it would mount up fine using just the forward bracket, but you wouldn't be able to get the rear bracket installed and on top of that it was out of alignment.

Looking back at it, the part number I provided for the LF20 forward bracket isn't the same as the one I am now using, so there is obviously some variation between engines.

What does yours look like?
 
Yeah so I think that front bracket should be fine, however the rear bracket probably won't work on the M54 as I don't believe the mounting holes line up. On the below link you'll see this is the pump and bracketry I have on my M54:


It's the single metal tab which sticks up and out from the back side

of the pump. This is the rear bracket for which I cannot seem to find a part number anywhere, but it's the only bracket I've come across which fits the M54 engine block.

Look at this thread on Facebook:
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​


Somebody has asked about the switch from an LF-20 to an LF-30 pump on an M54 engine and specifically about that rear mounting bracket (no p/n though). You can see the front mounting bracket is a big square piece and the rear is a straight-ish tab. Comments suggest you can get away with securing only the two front mounting bolts - depending on your level of risk, this is an option. Again though I would still caution to check the pulley alignment with the rest of the aux belt routing. If I recall correctly, it didn't sit in line with the rest of the belt routing when testing with the LF-20 'square' bracket - I don't recall what I found with the H bracket you have, maybe it pushes the pump out just enough to sit flush (perhaps it did work in the end for me without a rear bracket and I just felt the lack of rear mounting was issue enough to not use it).

(Thinking more about it since I did it, yeah the LF-30 pump was specifically a revision made at the time when the E46 was still being produced so it makes absolute sense that it will fit with some combination of front and rear mounting brackets)
 

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Hi all right this LF30 pump upgrade conversation is doing my nut in :ROFLMAO: I am shortly to start the pas conversion on my M54 2.2 I have been amassing parts for a while but unknowingly the E46 I took the complete system from used the LF30 pump, which I have since discovered will not fit regarding the pulley alignment, is there really no way whatsoever of making this work?
I realize I can fit the LF20 which I have in fact purchased but the LF30 pump to rack hose is different LF20 hose goes in the underside LF30 goes in the side and has a different thread size/diameter.
The car the system was taken from was a wrecked drift car so reg was not known and its now been scrapped so I cant even use the chassis number to try and find the correct hose, unless I want a lhd one of which there are many.
please please can somebody point me in the right direction?
ideally I would like to use the LF30 but if that's not possible then the LF20 will have to do but I will still need the hose
Does anybody know the right part number for a rhd LF20 to rack hose?
This is what I have now the LF30 pump to rack HOSE, I presume the LF20 hose will look similar just with a treaded union that goes into the bottom of the pump
 

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Hi there. that hose is for an Lf20 pump. The lF 30 has a banjo on both ends like this
 

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My hose installation on an N52. I modified a Z4M hose
 

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Hi Legin thanks for the reply, that hose came with the complete package I took from the donor vehicle, the hose was, until today, still attached to he LF30 pump and the purple tag rack, I took it off to take this picture, the threaded union does not screw into the aperture in the LF20 I have tried, it is a different thread and diameter, much head scratching and confusion this end.
looking at your first image is that a LF20 pump with the union at the bottom? I read the LF30 hose union went into the side of the pump as the one I have does...im very confused now
 
Hi again guys right I have mocked up the LF30 to a spare m54 it will fit bodily if only the 2 front bolts are used however the LF30 pump sits about 5mm further forward than the LF20, doesn't sound a lot but its about 1 rib of the drive belt so with the belt on all the other pulleys that 1 rib is always hanging over the edge of the pulley , turning the engine over as fast as I can by hand the belt is continually trying to ride itself off the pump pulley.
one other thing, I said on a previous post that the LF30 hp hose would not fit the LF20 pump, it will screw in but the depth of the threaded aperture is deeper than the length of the threaded union on the hp hose so while it does tighten down the hose can always move/rotate inside the union.
I'm thinking maybe my only option is to have a hose made to LF20 fittings as I cant find a RHD one any where, it's not even shown on realoem.com, the LF30 hoses etc are shown but not the LF20
 
If it helps, I've just completed a hydraulic conversion on my Coupe.
I found the high pressure hose tricky to sort. In the end I had the correct fitting for the rack and the correct end for my LF30 pump and got a company to 'fill in' the gap. I used LBA in Essex for the work, which cost £96 inc postage back to me.
I supplied the following info and they sent back the completed hose.
It fits and works perfectly.
 

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xantiaman said:
Hi Legin thanks for the reply, that hose came with the complete package I took from the donor vehicle, the hose was, until today, still attached to he LF30 pump and the purple tag rack, I took it off to take this picture, the threaded union does not screw into the aperture in the LF20 I have tried, it is a different thread and diameter, much head scratching and confusion this end.
looking at your first image is that a LF20 pump with the union at the bottom? I read the LF30 hose union went into the side of the pump as the one I have does...im very confused now
Click to expand...
Hi , Thats a LF30 pump fitted to an N52 so a 3.0Si. Banjo is LF30. The HP pipe itself I had to cut the steel tube shorten it , index it , reform the bends then rejoint it. So a total pita. I machined a sleeve then TIG welded fillet and plug welded it back to together. Having a hose made really is the best solution and it looks like the poster above has managed to find somewhere to do this.
 
xantiaman said:
The brackets for the LF30 are a large h shaped one for the front and a large triangle ish shaped one for the back
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I used an LF30 from a 2002 325ci in my swap, and it bolted right up and aligned fine (2003 3.0i). I have a few pics and videos in post #5 here which may help:

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Thread '2003 Z4 Hydraulic Power Steering Conversion'

Hello all. Haven't posted here in a while. Since my last post I've had my first kid so time has certainly been at a premium recently. I have been itching to get back to the Z4 and have been reading and researching doing a hydraulic power steering conversion upgrade. I know there are several threads on this already, so I hope this thread will add to the already collective knowledge that is out there.

A local junkyard got in a 2002 325CI earlier in the week and I decided to take a day off and go pull the power steering system out of it. Here's what I came home with:

laBcp9J.jpg...
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Keep in mind I'm still working the kinks out of my swap. Also not entire sure if LHD vs RHD plays into it somehow.
 
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