Hi, This is my first post. Lots of good stuff here, and a few fellow Canadians. I'm in the midst of rebuilding my waterpump and found this while looking for info. I have a question. BMW says seal installation requires a special tool. I've seen the usual websites and the UTube video, where everyone uses sockets to press in the seals. Has anyone actually seen or used this "special tool?" I'm curious as to what it looks like and how it compares with using a socket. Thanks!

Have you checked in the tutorial section? There is a document on changing the seal.
( Click here to access it )

@Diver wrote:I've seen the usual websites and the UTube video, where everyone uses sockets to press in the seals. Has anyone actually seen or used this "special tool?"

Yes, thank you.

Hi Diver,
I happily used a socket and rubber mallet to drive my oil seal and ceramic seal in
but it did occur to me that I could have made up a tool using a long bolt or
studding and selected washers and sockets to press them in if I wanted to.
I've done it manys the time when fitting the very similar water pump seals on a CX rear cover

I would imagine the 'proper' tool is similar to that and uses the same process
Pressing rather than driving the seals in would or should, allow you to ensure the seals
stay on axis and dont get skewed and distorted whilst being fitted

Its used to fit the shaft into the tight ceramic seal and I was doing Ok up till then when
I got ahead of my self, rushed things and buggered up the ceramic part

Instead of stopping to think I pulled the shaft against the face of the pump
instead of supporting the face of the seal and ripped the seal apart
Dumb Dumb Dumb !!!!!!
I did it properly the next time and alls well now.

Hmm, So the "special tool" that BMW refers too is used to pull the shaft into the seal? I thought from this, it was to press the seals into the housing:

http://www.ibmwr.org/ktech/water-oil-pump-rebuild2.shtml

I was hoping I might get a response from a BMW shop employee. I'd like to see the "official" tool, so I can better understand what I'm replicating. Thanks for your reply. I'll try to learn from your experience and be very careful installing that shaft.

Nice clear pics
Terminology differs, we all have our own ways of describing these things
If you use a hammer, thats what I call 'driving' it in
If you use nuts bolts sockets or a drill press, its what I call 'pressing' it in.

However we describe it, that the easy bit
You see the metal ring on top of of that seal?
That contains the ceramic part that spins and makes the seal water tight
Very delicate, Very !
This is what you need the support when you pull the shaft through until the
oil pump gear becomes flush with the inner face of the oil pump body.

This when my lack of attention/tiredness/impatience whatever broke the thing
the rest of the jobs pretty straightforward

I will add that when refitting the pump you ensure the smaller oil pump wheel
is properly engaged in the engine body and when you turn the impellor to align
and fit the pump, you check the pump fits face to face and doesnt sit up to one side
before you tighten the bolts.
That would be a costly mistake, I know someone who did that.
My own gaffe was minor in comparison.

When I fitted my pump I found I had fixed the water leak only have a small oil leak
and had to remove the pump, clean off the inner face and re-apply sealant.
this is another part of the job worth taking time over to avoid extra work.

@reg_K100RS wrote:
If you use a hammer, thats what I call 'driving' it in
If you use nuts bolts sockets or a drill press, its what I call 'pressing' it in.

That's what I would say. A mechanic friend gave me some Loctite 515 Flange Sealant. He says its the best so I'll try that on the joints. Did you oil the outside of the oil seal before installing it, to make it go in easier?
You just gave me an idea. Maybe I should press it in with my drill press.

Normally driving the seal in with a socket and extension piece will allow you to get it in properly without issues if the pocket is properly clean. The issue is getting the pump shaft through the seal without damaging it. The instructions make that clear - slowly pull it through whilst ensuring that the seal is supported. You can use the old distance piece with some rings, but in order to keep the seal good you have to pull it through whilst supporting the seal, otherwise you'll break it. Very easy job, just do it easy/carefull.

Well, I've got the seals in but the water seal isn't tight to the casting. It seems like it won't go any further though. The edge of the flange that you drive, is sitting up almost 1/8 " above the casting. Is that the way it should be, or is it supposed to in further? Is it supposed to be flush with the casting?

It is supposed to be flush. when you get to the level where the blue sealing material is applied it becomes more difficult to get it in.

It seemed that I was hitting it but it wasn't moving. I was afraid of damaging it so I stopped. I guess I'll have to hit harder now. I was afraid of deforming the flange where the socket is making contact.
Thanks!

Did mine a couple of weeks ago
I tapped mine down flush as well and dont recall having to go mad it it either

OK. I guess I was just a little over cautious. I got it in now. She's definitely a snug fit. Next comes getting the shaft through the seal.

Make sure you support the seal whilst getting the shaft through. Push the haft until you feel resistance and then pull it through wth the spacer bush and rings and the nut. By tightening the nut with the filling pieces in place you support the seal whilst pulling the shaft through.

Thanks Rene. Good advice from the land of my ancestors! Some guys oil the shaft to make it slide better. I'm wondering if that will affect the sealing properties, since the blue goo on the inside of the seal contacts the shaft to keep the water out. My neighbour, a factory trained BMW car and bike mechanic, says the factory "special tools" for the numerous seal penetrations all use cones to ease the entry of the shaft into the seal. He said when they don't fit, they improvise a cone with a piece of paper and suggested I do the same.

I would not grease the shaft. It is important that the blue goo sits on a clean shaft so it can seal. I wonder if there is oil or grease that it will seal properly.

Better late than never I suppose...

Here are a couple of videos I found on the K11OG forum for the water/oil pump seal replacement.

They are for a K1100.

https://www.youtube.com/watch?v=_CBtaioRMx0

and

https://www.youtube.com/watch?v=j8JUY8C2c08

I haven't seen them myself, but the feedback given says that it makes the job a bit easier.

Hi again. Well, I got the shaft through both seals OK, except now I'm a little worried that I may have overdone it. It was going good and I may have given it a few more turns than I should have. I've compressed the spring in the waterseal, and there's a gap between it and the spacer that backs up the impeller. Is this going to cause problems? What do you think?

It was real tight, with a lot of resistance to spinning of the shaft. I pondered it, and got my neighbour the BMW tech. to check it out. Verdict: too tight, so I took it out and of course broke it in doing so. Got another one on order. I'll be more careful next time. Stay tuned.

What I saw people doing is to remove the pump, clean everything and have the dealer installing the seal. This way, if the mechanic breaks it, the dealer has to replacing at its cost.

They offered to do that for me, but the labour charge was equal to 2 seals.

Well, sometimes you have to bite the bullet.
I replaced the seals on 2 pumps and didn't experienced any problems.
A friend of mine (licensed mechanic) got some problems to replace it and went to the dealer.
This seal is the most difficult repair on a K100. If you succeed, you can do anything on the bike.

Crazy Frog, if you say that the most difficult repair on the K100 is the waterpump seal, can those people who have changed one successfully, add "I've changed a waterpump seal" to their signature as a form of bragging rights?

Well I know now I can do it. I DID it, but I didn't know when to stop. It actually went in pretty easy. Getting it out was the hard part. That's a real tight fit.

Oooh, I could say something there, but I won't!

@blakey wrote:Oooh, I could say something there, but I won't!

We can just imagine....

never mind Diver
Welcome to the
"I screwed up the first one" club



I found my mind was very attentive and focussed doing the second one

@blakey wrote:Oooh, I could say something there, but I won't!

Go right ahead. I can take it! I've opened the door to endless possibilities for hijacking this thread.

Member: I screwed up the first one club.

"Well I know now I can do it. I DID it, but I didn't know when to stop. It actually went in pretty easy. Getting it out was the hard part. That's a real tight fit."

I was going to say "that sounds like an old girlfriend of mine".

Got her phone number?

Diver, you never did finish your story.
Was the second install the charm?

OK, you have a 1985 model (seems), as I do, was your impeller the cast iron type?
If so, what did you order or get from the dealer in order to adapt the new type of water-pump seal (ceramic type).
Did you change to the newer type of stamped steel impeller?

I just pulled mine apart, my impeller is cast, and my seals were the standard type, although the water-pump one did have a little spring in it.

I just would like to order anything I will need to do this repair in one shot, hopefully no return trips to the dealer.

Thanks in advance,
Rick

Rick, They had to backorder the 2nd waterseal. I just got it in last night, but haven't yet reinstalled the pump. I had the cast impeller too. I guess that means its original. To upgrade, you'll need the newer stamped impeller, the spacer, oil seal, water seal (new style, I don't think the old one is even available), small O ring for the small gear shaft and large orange (silicone) Oring for the coolant passage. The new impeller won't fit on the old shaft, so you also need the newer style shaft, which uses a bolt instead of a nut, so you'll need the bolt too. I think that's it. Be really careful installing that seal. I used a 1" socket to drift it in. The large gear fits flush to the casting. When you get it in that far, stop pulling. Good luck.

Driver, can you send me the part numbers with descrption of each number so I can be sure to order it all?
I would REALLY appreciate that!
You say I need a new shaft, does that new shaft come with the gear on it?

Thanks,
Rick

If you're ordering from a dealer they'll have a picture with all the parts and the numbers, and the expertise. No dealer near you?

I called the dealer, no dealer real close.
I got a kid I think, anyway all he has coming for me was 4 seals.
I did not get the numbers on the phone, but the price was $86.45, so I know there is no impeller or spacer or shaft in that order...

So, do you have numbers?

Rick

Sounds like you need to talk to the kid's boss. Man there's a whole lot of numbers. OK, Here goes:

(my comments in brackets) $CDN

11-41-1-461-793 Roller Shaft (gear & shaft=one piece) $199.69

12-31-1-460-853 Bolt $1.71

1-41-1-460-329 Seal Ring (oil seal) $9.66

11-51-1-704-084 Gasket (waterseal, AKA Slipring seal) $39.66

11-51-1-464-902 Bush (spacer I think) $8.57

11-41-1-461-173 Rotor Oil Pump (must be the impeller) $24.09

11-41-1-460-328 O ring $1.36

11-51-1-464-392 O ring $1.91

Have fun!

Ouch...! That roller shaft is a big bite.
Makes no sense that they discontinue a certain seal (which lasted 25 years), only to replace it with one that is really fragile, and requires 100's of dollars of replacement parts just to accomodate it.

Wow...

Thanks Diver,
Rick

Well, that's a bit short.
The new shafts were a modification as with the old ones at times the threaded part with nut broke loose and ate its way through the pump cover - big mess.
You need to be very careful if you intent to order the shaft as they made a modification over the years whereby the new gearwheel has more teeth than the original one; so if you get a new shaft with gearwheel you might need a new drive wheel as well.
The 4 seals are probable the waterside, the oil side, the housing one and the little one that's fitted on the drive shaft (little gear wheel shaft). I seem to remember that when you change from an old cooling water seal to a new type you had to change the spacer bush behind the pump rotor. That's all.
If you have the pump off and open, check if the weep hole is open. I've just done a pump and it was solidly blocked.
When you are getting the shaft through the new seal make sure you support the seal by pulling the shaft through the seal with spacers (I used the original bush + steel rings) etc otherwise the ceramic part of the seal will fail.

The cast impeller was thick in the centre. The spacer makes up that thickness along with the much thinner new stamped impeller. The part # I posted for the shaft mated with the older style, fewer teeth, drive gear in my 1985. The price is a little steep, but production costs aren't cheap in Germany and I don't mind paying for quality. It will outlast the bike. The design was improved in later bikes and made to retrofit the older ones. It makes sense. I took the bike for a ride yesterday. So far so good.
Use Loctite 515 Flange sealant between castings. Its the best.

Thanks Diver.
I intend to keep my original impeller & shaft.
I will use the 11-51-1-704-084 Gasket (waterseal, AKA Slipring seal) and see what happens.
I have spoken with others who have used this seal with the original 1985 vintage impeller & roller shaft with no problems after many kiloms.
Hopefully Murphy will not be anywhere around.

Rick

Hope it works OK for you. My shaft was very badly pitted so it needed replacement anyway. I got a spare old style cast impeller now.
Got 150 kms. on the new pump now.

Well, Murphy was there with me till the very end, and in the end once it was all back together, it leaked coolant out the weep hole...
I guess I just don't get how I "support the water seal" when I'm pulling the shaft through.
When I stacked a stack of washers on top of the seal (small end) to be able to pull the shaft through, I completely compressed that spring loaded seal.
How else can it be done?
The small end is spring loaded, and as I tightened the nut against those washers it seriously compressed that spring loaded part as much as it could, that shaft is a tight fit, and requires quite a bit of pressure to get it through.
I did get it through, but then as I installed the impeller, by using the nut to compress it onto the shaft I saw that there was absolutely no space left for the spring loaded part of the water seal.
In order to get the impeller back to where it was positioned when I removed it, I had to completely compess the water seal to where there was no more compressability left.
It was butted, I think that too was traumatic for the ceramic part of the seal.
So, I'm not sure exactly how I can re-do this other than to do like Diver and buy the shaft with gear, new impeller, spacer, bolt and of course 2 more new seals.

I do have a question that will help me understand this problem I wound up with: does the spring loaded water seal maintain its full range of compressability once properly installed?
If it does, then the shaft with impeller & oil gear will also have an equal amount of fore / aft movement range, which seems strange to me....that means the shaft with both oil gear & impeller would be "floating" in the housing......is that correct?

Thanks in advance
Rick

Sounds to me like the old shaft maybe isn't long enough to accommodate the new seal. My old seal was completely destroyed and came out in a million pieces so I can't compare. Maybe in order to clear the threaded portion of the shaft, you had to compress the seal. The new shaft has the threads on the inside, so more length is usable. Does that make sense?
I examined the seal that I wrecked to find out how it works. The outside remains stationary in the housing; the inside spins with the shaft. Each has a ceramic washer attached, backed by a rubber cup. The washers meet face to face and make the seal, and the mating surfaces rub as the shaft turns. The spring forces them together so one is always pressing against the other.
If you have enough shaft length, put a bar across the housing with a hole in the centre; fill the gap between the bar and the seal with washers, and pull it through like that from the outside of the bar. That way you're not bearing on the seal and it can't move.
I wiped a little grease on the shaft too, and on the oil seal as well.
Good luck!

Rick
Dont feel too bad, a lot of us have struggled with this one.

Thinking about it
With the ceramic seal supported, the spring should not compress at all
when pulling the shaft through
as theres nothing to pull against unless you butt the oil gear up against the
inside of the case.

During my first fiasco
as well as not properly supporting the ceramic part whch destroyed it.
I pulled the shaft until the oil gear was hard against the
inside of the case and this compressed the spring
it was hard to turn the shaft like this and like an idiot i fitted it anyway
until I came to my senses.

The next time I pulled the shaft though until the oil gear was flush with
the mating face of the case
then I stopped and checked it spun easily
Then I measured the amount of shaft protruding from the seal and checked
and made some adjustments with washers until it matched the
internal depth of the spacer.
This cpmpressed the spring a bit as I recall.
It didnt take lot of effort to pull the shaft through
as its only a thin metal assembly.
The rest went smoothly much to my relief.

the only snag I had was a slight oil leak between the oil pump faces
due to being a wee bit hesitant about applying sealant
but as I was an expert at whipping the buggers off by now, it was
no big deal to rectify that.

Reg

@reg_K100RS wrote:
I pulled the shaft until the oil gear was hard against the
inside of the case and this compressed the spring
it was hard to turn the shaft like this

That's what I did. Then I removed it and started over.

@reg_K100RS wrote:
The next time I pulled the shaft though until the oil gear was flush with
the mating face of the case then I stopped and checked it spun easily

That's exactly what I did. And that's where I stopped.

A couple of weeks ago I noticed oil in the coolant expansion tank of my 1986 K100RT. Aha I thought probably pump seals, and duly ordered a seal kit from Motorworks. Of course being the bright fellow that I am I ordered the kit before I stripped the pump, assuming (or hoping) that it would have the later type shaft. Of course when I opened it it turned out to be the early type with the nut and the cast impeller. Anyway I stripped it, cleaned it, removed the old seals,and fitted the new ones all without any trouble. I re-fitted the shaft and then sized up the impeller. There was no way it was going to fit without binding against the water pump seal and compressing it. I measured the depth of the recess in the back of the impeller and the length of shaft from the face of the seal to the face of the shaft at the base of the threaded portion, and reckoned that if I could grind about 4mm from the impeller that it would fit.
I did just that and it was fine. Now all I had to do was fit the nut and tourque it up. I figured that the shaft had lasted this long without breaking that it should be all right. I should have known better!!!!!! I'd only just nipped it up "wrist tight" when the dammed thing sheared off. Of course I couldn't get the shaft out without making bits of the seal. Now I've got to go and do what I should have done in the first place, order a new shaft, impeller and another pair of bloody seals. It might be easier to just order a pump! Motorworks have them for around £225 sterling.
So if your pump has the old type shaft, no matter how good it looks, dump it. It will save you a lot of grief.

Avenger, I basically came to a similar conclusion.
The impeller would have to be ground down, or milled off by about 4mm in order for the water seal to have any spring compressability.
So, I might just do that, and face the possibility of shearing the shaft on installation, or I might buy a whole new $199.00 shaft.
I will drink on it, I mean sleep on it...

The other issue is pulling the shaft through the water seal.
Mine was so tight, and with little more than the threads sticking through the seal, there is no way I can figure to get it through with-out squashing the water seal as I tighten the retention nut against a stack of washers....

Are all of you pumpologist's who have successfully done this job able to simply pull the shaft through the water seal by hand?
I do not see how it is possible for me to do that with-out seriously compressing that seal, the seal just compresses as I tighten the nut on the shaft.

So what am I not seeing here, how else can I get the shaft through?

Thanks in advance,
Rick

I pulled mine through with the new bolt and some washers, and a light grease coating. Had to use a 3/8 drive ratchet.

Diver, by that description I would think you had to completely compress the waterseal correct?
So I guess that squashing it like that doesn't really damage it?
When you were done, and the impeller was installed was there any play left meaning could you push the impeller in towards the seal, using some of the "free-play" of compressability of the waterseal?
Or was the seal compressed to the point that there was no movement of the impeller (in/out) ?

Rick

It didn't appear to be compressing, but perhaps it did. There is a sticky blue sealant on the inside of the seal which binds it to the shaft, preventing any possible movement. The first time I did it, the seal did not compress. When I got the shaft in all the way, with the gear flush with the housing, I should have stopped. I gave it a couple of more turns for good measure and that's when I compressed the seal. After that the shaft was too tight and wouldn't spin freely.