Power steering pump rebuild

Finding this is SOOO timely as I have my PS system drained. It was groaning excessively and the oldtimer I chat with recommended complete fluid replacement rather than just topping up. A change worked well for the E30, now for its older brother.
 
Nice one Steve! I recently replaced the nose shaft seal on mine, as it had begun to leak in a very tedious way. I agree with you re the roller bearing. I thought it was a joke at first, but managed to get my rollers to stay in place with a little grease while the shaft is reinserted, otherwise they kept falling out and testing my vocabulary! No leaks now and a bit quieter on new fluid too.
 
this is awesome I just ordered what I could of the seals and bearings that are still available at the site listed above but what about the steering box itself is there a good source for all the seals and bearings for the power steering box itself?
 
I found that rather than just replacing the fluid in the reservoir, a complete drain and refill made my groaning go away. But I think in my case, simply driving more often would be the hot ticket. We all know coupes in particular and early bimmers generally, all need regular exercise. Just like their owners.
 
Hi, I have my parts and have taken the key and the circlip off the front and back, now how do I get the back off?
All help accepted.
 
Mark Wilson said:
Hi, I have my parts and have taken the key and the circlip off the front and back, now how do I get the back off?
All help accepted.
Click to expand...

Well, I managed to get the back off eventually, A think it had been put on with shellac. I managed to clear it off and then pop the back off with a bit of air pressure ( it always makes you jump).
The rotor housing was a real pain to get off, but I managed it and now I'm stuck on the backplate. I made a bit of a puller, but it bent under strain. So I think the previous repairer might have used some more magic to seal it in. I was thinking about putting some heat on it.

Thoughts please?

Thanks
 
Mark Wilson said:
Well, I managed to get the back off eventually, A think it had been put on with shellac. I managed to clear it off and then pop the back off with a bit of air pressure ( it always makes you jump).
The rotor housing was a real pain to get off, but I managed it and now I'm stuck on the backplate. I made a bit of a puller, but it bent under strain. So I think the previous repairer might have used some more magic to seal it in. I was thinking about putting some heat on it.

Thoughts please?

Thanks
Click to expand...


photos please ?

it will make easier to help
 
Mark Wilson said:
Hi, I have my parts and have taken the key and the circlip off the front and back, now how do I get the back off?
All help accepted.
Click to expand...
Mark, just in case - On Oz Ebay, this -
BMW 2.5CS-3.0CSL Coupe Power Steering Pump Fits up to 04/1981 Ref Part 1124085
 
Might i suggest moving this post into the DIY section? It's been a very helpfull explanation by @Stevehose ; as I'm about to do the same this is helpfull to understand how it all goes out and in again.

My pwr str pump has no problem, im going to rebuild it for peace of mind as it's out of my car anyway....
 
Knocking the dust off this very helpful thread I found the cap seal/oring is now obsolete.
32411105157
Google is not steering (no pun intended) me to a new part #.
Does anyone know specs on the oring? Realoem doesn't provide one.
 
If you can find the dimensions, I have had good luck with orings.com.
 
Ohmess said:
If you can find the dimensions, I have had good luck with orings.com.
Click to expand...
I've used them before and have a shopping cart full of guess sizes. Thanks!
I am guessing on size and would probably buy a few sizes in the ballpark.
Really hoping someone knows the exact size.
 
Thomas76 said:
Knocking the dust off this very helpful thread I found the cap seal/oring is now obsolete.
32411105157
Google is not steering (no pun intended) me to a new part #.
Does anyone know specs on the oring? Realoem doesn't provide one.
Click to expand...
Hi Thomas
I think I listed the size’s when I rebuilt my one .
Hopefully it might be helpful for you.

Shaft seal on hydraulic steering box

I sent mine (and PS pump) last week.
e9coupe.com e9coupe.com
 
Barry.b said:
Hi Thomas
I think I listed the size’s when I rebuilt my one .
Hopefully it might be helpful for you.

Shaft seal on hydraulic steering box

I sent mine (and PS pump) last week.
e9coupe.com e9coupe.com
Click to expand...
Thanks for reaching out, I reviewed the post and found the picture of receipt. There are multiple 2.62mm orings with diameters very similar, I'd still be guessing unless you know which one specifically landed in that pump cover?
 
Hi Thomas
Unfortunately I cannot remember which one went where as I replaced all of them at the time.
 
eriknetherlands said:
I ordered most/all of the replacement parts one or two years ago when this wonderfull thread was started. I still have them in a bag - I'll measure that one (32411105157) up for you this evening.
Click to expand...

Here is the measurement; it looks to be 2.6 mm thick.

The ID/OD can't be measured, as it is sooo floppy.
Perhaps it works as follows: if the O-ring is half burried in the housing (an assumption; needs a check), one could measure the ID of the hole, and add 2.6mm to get the OD of the ring.
 

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eriknetherlands said:
Here is the measurement; it looks to be 2.6 mm thick.

The ID/OD can't be measured, as it is sooo floppy.
Perhaps it works as follows: if the O-ring is half burried in the housing (an assumption; needs a check), one could measure the ID of the hole, and add 2.6mm to get the OD of the ring.
Click to expand...
Thanks! I'll give it a go and post results with part number when done for the next fella.
 
Update:
I bought 2.5mm orings from orings.com, they did not have 2.6 or 2.7 in the correct od.

The new oring does not seal the cap. :(
2.5mm is noticably smaller than 2.6 and I believe that could be what went wrong.
The design intent appears to have the cover pushed against the oring, not through it if that makes sense. The snap ring places a squeezing force on the oring that doesn't happen with the smaller diameter.

It is also possible the mating parts are simply old and worn creating slop that a new oring won't fix.
 
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