I'm having some issues trying to replace the pushrod seal on my K. Seal was sourced form Motobins, part number 'BMW: 23 21 1 451 159'

Read every forum I could find, and the manual which says "Carefully lever out the shaft sealing ring (arrow) with a screwdriver". Also saw advice to use a pick or screw to extract it.

Found a big screw and opted for that, with the backup of the screwdriver, because I couldn't find my pick.

Anyway, the screw just wouldn't bite, even though it looked like it was the right size. So I tried gently levering with a small screwdriver. Things didn't go well, the rubber kind of fell apart, the spring inside got damaged, and the inner lip of the seal broke away, but the rest seems pretty stuck in there. I've attached a picture of what came out, and what the seal now looks like. It seems like the seal is stuck to the housing, and is brittle. I'm pretty concerned about going to hard in there and doing some serious damage, so wanted some advice on the best way to deal with this.

I have a feeling that there is a metal washer\ring inside the seal, which it what I've gotten down to with the screwdriver, but it could be the housing underneath it.


So, 2 questions:
1) what's left of the seal, and what's the best way to remove it?
2) the spring that came out, I didn't see much info about that, wasn't even expecting it, was I supposed to save it and re-use it with the new seal? will I need to get a new one?


Let me know if you need better pictures.

The outer case of the seal is steel so you need to be a bit brutal.
There is nothing down the hole you can damage try an internal expanding claw and slide hammer.
Be sure to replace the seal with the internal tension spring facing outward (that's the coil spring) because the clutch side is the outside.

Thanks Rick, 

Its nice to know what the thing I'm trying to rip out is made of, and that I can't hurt anything in there.

I'm still a little confused about the spring though. Is there one buried in the rubber of the new seal, because I can't see one in there? Or am I supposed to put the old spring in the lip of the new seal?

The new seal may be a Teflon seal in which case there is no spring. The seal lip will be whiteish if it is Teflon and be careful when inserting the pushrod that the seal doesn't turn inside out, twisting the pushrod works well.

Thanks again Rick.

I'm starting to think maybe motobins sent me the wrong seal. I can't see a spring or a white Teflon seal. It looks to be the right size, and has the right part number, but its not metal like the one they have pictured on their site. I've attached pictures if you/anyone wants to weigh in on this.

Although it does look a lot like this one, so maybe it just isn't metal anymore, and motobins hasn't updated the picture. https://www.motobrick.com/index.php?topic=11262.0

Also, I might have to invest in the expanding internal claw you mentioned. I tried a mini pick set this afternoon and the thing wont move at all.

It looks like the right seal but measure it to be sure the second pic is how it looks as you push it in. The material is quite thick around the lip and as there is no pressure it should do the job.

Thanks again Rick.

Still need to get the seal out, but at least I've got something to replace it when I do.

OK, I'm stuck on getting this seal out. Doesn't matter what tool I use it doesn't budge.

I've tried everything from a wall anchors, to pics, to screwdrivers, pliers, etc, etc...

Rick, I've tried searching for the "Internal Expanding Claw" tool, but only seem to find pickup tools. I'm not sure its would be able to grasp it any better than what I've used, but I'd try anything at this point.

Should this be so hard to get out?
Should I try WD40 or some penetrating oil?

Any suggestions would be welcome.

Try Total Tools, Trade Tools, Sydney Tools, Repco or Bursons.
Regards Martin.

Point a hair dryer or heat gun down the bore where the seal fragments are located. Heat the area for a minute or two. Spray in Liquid Wrench, Seafoam or an equivalent rust penetrator. WD 40 won't be nearly as effective as those but if it's all you have, give it a try. It might smoke a little when the spray hits it. Take a break for a few minutes then use a long punch or dowel tapping the fragments lightly to break the corrosion then drag that junk out of there.

Take care inserting the repalcment, there is no shoulder to stop it going in too far.......

Thanks MartinW, I had a tried most of those already, but there are a couple there I can try as well.

92KK 84WW Ola, I'll keep that in mind when reinstalling. Might add a washer to the tool I made to install it.

And Laitch, that's given me a way forward. You're probably right and its a bit of corrosion locking it in there.

The top photo in post 5 gives a clue to this problematic seal. You will see the seal is stamped PIA. Does the maker mean the seal is a Pain In the Arse (PIA)?

Get the largest flat blade you can manage into it at a shallow angle and tap it behind the seal.

Square shank works best but if you don't have one, vice grip on the handle will work for rotational leverage.

Gently twist the driver to lever the seal away from it's seat.

Be careful to not be hard up against the outer wall where the seal pushes in.

lol PIA... that is written on the new one, maybe it was a warning.

I'm throwing in the towel on this one, and I'll find a mechanic to take it out. Tried heat, and every tool I have to try and move it, but no joy.

ok, Seal is finally out. Shout out to Scott at ProCycles who fit me in despite being super busy before the Christmas break. Took the mechanic the best part of half an hour, it really didn't want to leave its home.

For anyone who encounters this issue in the future it ended up needing heat, and a slide hammer placed very precisely. There is barely any lip left if the rubber of the seal breaks apart, as the metal part of the seal is only slightly bigger than the barrel the pushrod goes through. Picture of the actual tool used attached, just in case it helps.
 

Thanks again for all the suggestions and help. You guys are awesome. Rick, as soon as I saw the tool he used I immediately knew what you meant by 'internal expanding claw and slide hammer", you were spot on.