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.

The seal does not compress enough to damage it when you pull the shaft through using washers. I used a little light grease on the shaft and it pulled through quite easily. The tightest part of the assembly is the center of the water seal where the "blue goo" is, so you are only pulling against the center of the seal. However when you remove the broken shaft you are putting all the pressure on the water seal and the first thing you hear is a little crack as the seal disintegrates.

Avenger GT wrote:However when you remove the broken shaft you are putting all the pressure on the water seal and the first thing you hear is a little crack as the seal disintegrates.

OK, I think I heard that crack sound, I thought I had pulled the shaft through a little too far, maybe .010", so I put the assembled housing & shaft back on my Drill Press to push the shaft back just a bit.
I thought I heard something crack.
That is probably when I ruined the seal, as once fully re-installed my pump leaked coolant right away.

Nothing left to do but try again.....
Thanks all for your patience, and input.

Rick

Every day we learn a little more, usually the hard way. I have decided to go the new pump route, should have it by the weekend. Hopefully I should be back on the road next week. I'm beginning to get withdrawl symptoms with the fine weather at the moment and no bike. Fine weather can not be taken for granted in Ireland!!!!!

Team, I wonder if you received all the parts. Normally the new seal comes with a new spacer bush. Furthermore the seal should not be really compressed when you pull it through with a bolt and washers as the shaft seal is on the bit that is supported by the spacers. It could of course be that the shaft is 'sticky' on the new oil seal, but a bit of oil on the shaft should prevent that.
It is important that the gearwheel part ends up against the housing. There should be no clearance between the big gear and the housing. If there is the pump can not work. Normally the gearwheel with shaft will then be pushed in place once fitted against the main engine housing, but then your pump seal will have problems. I had an old pump on the bike, but bought a used one complete on fleabay and refurbished it with new seals. No real issues and it works like a charm. Just don't do it on the morning after the evening before ;-)

ReneZ wrote: Furthermore the seal should not be really compressed when you pull it through with a bolt and washers as the shaft seal is on the bit that is supported by the spacers. It could of course be that the shaft is 'sticky' on the new oil seal, but a bit of oil on the shaft should prevent that.OK, so how do you pull the shaft though with-out really compressing that seal, because as in my case, that shaft was impossibly tight?
The stack of washers sits on the small end of the seal, and as soon as I started tightening the nut against those washers, that seal completely compressed.
It is important that the gearwheel part ends up against the housing. There should be no clearance between the big gear and the housing. If there is the pump can not work. Normally the gearwheel with shaft will then be pushed in place once fitted against the main engine housing, but then your pump seal will have problems. I had an old pump on the bike, but bought a used one complete on fleabay and refurbished it with new seals. No real issues and it works like a charm. Just don't do it on the morning after the evening before ;-)

Thanks ReneZ,
Rick

Avenger GT wrote:Every day we learn a little more, usually the hard way. I have decided to go the new pump route, should have it by the weekend.

That was my first choice. I went to my local dealer. The cute little parts chick showed me a diagram on their computer. The entire pump assembly was indicated as such by a couple of large brackets including all the exploded components. I asked for and received assurance that everything within the brackets was included in the assembly, which had one all-inclusive part number. The price was about $300. I paid up front and waited 10 days for the special back-ordered part to come from Germany. When it arrived it was only the cast housing. The real parts guy said someone screwed up; the computer showed that the assembly wasn't available. I explained my assurance and was promptly given a refund. I hope you do better. Good luck. Nice riding weather here in Canada these days! I've burned almost a whole tank of fuel now.

Both Motorworks and Motobins in the UK have complete pump assemblies. Cheaper at Motorworks but they will not send to USA or Canada, for whatever reason. Can't see anything on the Motobins site to say that they don't.

http://www.motorworks.co.uk/bmw/products/product.php?f=i&code=BA_15_40_BA_60&shnew=New&model=K75%2F100%2F1100&shnewcode=15&part=Engine&sub_part=Water+pump%2Foil+pump&modelcode=40&partcode=BA&source_code=BA_15_40_BA_60&header_text=&header_text_image=0


http://www.motobins.co.uk/bmw-parts.php?model=K Series

[quote="Avenger GT"]Both Motorworks and Motobins in the UK have complete pump assemblies. Cheaper at Motorworks but they will not send to USA or Canada, for whatever reason. Can't see anything on the Motobins site to say that they don't.

http://www.motorworks.co.uk/bmw/products/product.php?f=i&code=BA_15_40_BA_60&shnew=New&model=K75%2F100%2F1100&shnewcode=15&part=Engine&sub_part=Water+pump%2Foil+pump&modelcode=40&partcode=BA&source_code=BA_15_40_BA_60&header_text=&header_text_image=0

There's more teeth on those gears than on mine.

There's more teeth on those gears than on mine.

The later pumps have more teeth, but that doesn't matter since they are only meshing with each other, and not with any other gear. The early type gears / shaft are available seperatly. I just added up the cost of the seperate parts and decided that for the extra few Pounds/
Euros/Dollars I would be better off with a new pump.

I came to the same conclusion, the same way.

I came to the same conclusion, the same way.

Great minds thinking alike!! Or fools seldom differing!!

Avenger GT, what did you do with the milled down (4mm) cast impeller?
Want to sell it?
I would like to see if it will work with my set-up.
Holy Molley...you're in Ireland...OK...I already know the answer..

Rick

@ FAK - re compressing the seal. I can only conclude that the shaft was difficult to get through the oil seal. The compression of the seal to a certain level will not harm the seal as long as the force applied is regular and slowly build up. The water seal holds two ceramic rings which are spring loaded to keep them in contact. Instead of having a seal running over the shaft the shaft has a stationary part and the housing has a stationary part. Both have a ceramic running face that is spring loaded to keep them in contact. It is not difficult to do (really!) just take your time and go slow. If stuck, don't force, but ask. Or spent loads of money and buy a new pump.

Hi fellaz, well I finally got around to re-building my water / oil pump again.
After much discussion here, and taking notes, I have a functionial pump once again.
I replaced both oil & water seals, got rid of the original cast impeller, and went with the "newer style" little bushing & stamped steel impeller.
The second time around I was much better equipped, and the job went very easily.
So, from now on, whoever still has the old cast impeller and needs to re-build the pump, I say skip that part, and the job will be a one hour affair. (The cast impeller needs to be milled down by 3.8mm to work with the new type water seal)

My road test revealed no leaks.

Thanks to Diver, ReneZ, Avenger GT, and of course Crazy Frog for all their help.

Rick

Glad to hear it. I first knew I had a problem when changing the oil. Oil came out looking OK but when I dropped the filter cover a gush of water came out. Since rebuilding the pump I filled it with cheap 15W40 Diesel oil I had laying around. I wanted to be sure the repair was good and not waste good oil if it wasn't, and also flush out the crankcase and clean her out a bit. Between the rain and my to-do list I haven't yet got 500km on her, but when I do, very soon I'll put some good oil in her. Now I need to find some black crash bars. Anybody?

Back on the road just over a week and 300 odd miles. New pump is a little different to the old one in that the gears have smaller teeth, and the small gear is smaller, and the large gear larger, meaning that the water pump impeller turns more slowly. Probably makes no difference to water circulation as the vanes on the steel impeller are deeper than the old cast one so it takes a bigger "bite". May even help to avoid cavitation at high revs.
Anyway so far so good, I even fixed a small but annoying oil leak on the timing chain cover which was there since I got the bike over five years ago. I know I'm lazy, but if it's not something that will cause the bike ( or car ) to stop up on the road I tend to tolerate it till I can get round to fixing it.

Great news, glad it worked out!!

Hi, I just did the water pump seals, how do you know if all is well?do you have to run the bike? the gear turns pretty smooth, would it not if the seal was broken?

Thanks
Brian

yankeeone wrote:Hi, I just did the water pump seals, how do you know if all is well?do you have to run the bike? the gear turns pretty smooth, would it not if the seal was broken?

Thanks
Brian

Sorry, but the only way to test it is to run the engine.

The gear will still move just fine even though the newly installed seal has been compromised during the install.
True story.....

Rick

The pump seals work! Thank you for your help,
Brian

1. Is this shaft eligible for replacement? (pits are not deep)



2. Is there a special grease to affix the seals in the housing?
3. What do I need to buy a new to repair the old type pump:
- 11511464902 SPACER BUSH
- 11411741870 SLIP-RING SEAL
- 11411460329 SHAFT SEAL - 12X25X5
- 12311460853 SCREW - M8X22
- 11411460328 O-RING - 7-2
- 11111460392 O-RING - 27,3X2,4
- 11411461173 ROTOR
anything else?

Assuming that is the actual gear and shaft, and not a typical example, I would be more concerned about the scores around the gear face, how/why they are there and condition of the casing. Gear pumps rely on minimal end clearance to prevent bypass. I suggest you have a really close look at the mating components of the assembly, some lapping may be required to get back to tolerance. The engine may have gone for extended periods between oil filter changes, in which case the filter bypass valve may have been opening.

I will mill the gear face on the lathe to remove scratches. I will fit the housing to get the desired tolerance

What should be the clearance between the housing and gears (big and small)

Haynes manual states that there are no service limits given, and also no operating pressures are stated, only the minimum pressure range that causes the oil pressure light to come on (3 - 7 psi).
As for the pump internal end clearances, I suggest for a gear pump of that size you need to aim for aroun 0.05 mm (0.002") maximum end clearance (gear face to cover). Check it using Flexi-gauge, do you know the stuff ? Looks like plastic spaghetti and is available in different measurement ranges. Place it in the space (hold with grease), assemble components dry, dismantle and use the scale on the packet to measure the flattened width, which translates to the thickness. The final oil pump assembly must be done very carefully in respect to achieving an oil tight joint at the front engine face. This is a high pressure joint (full pressure before the relief valve). BMW states 3Bond 1209 I think. I used Loctite 515 Master Gasket with the mating surfaces primed with Loctite Primer T and allowed to cure. Do not touch the primed surfaces before applying the 515.
Good luck, hope this helps.

Using Loctite activator (now is 7471) is necessary?

I can only speak from my own experience with my water/oil pump rebuild. I tried twice to effect a seal without priming, but no luck, oil still weeped from the joint, can be felt by poking little finger in the hole the oil pressure switch wire emerges from.
The primer chemically etches the surfaces, preparing them for the curing process for the 515 Master Gasket.
I experimented with the effectiveness of the primer by applying it to 2 zinc plated bolt heads then applying the 515 and allowing to cure, vs just applying the 515 to 2 other bolt heads. The difference in force required to break the seal is quite amazing.
Loctite products cure by removing the air (anearobic curing process).
I couldn't obtain the 3Bond product, so the Loctite had to do, that was 2 years ago, no problems since.

In service manual K1100LT BMW don't say anything about Loctite between the engine and oil pump housing...

I know it's not an argument...

Loctite 518 this Loctie is quite stronger

or Loctite 5188

Now I have all of the issues sorted and had a good ride on the bike today it has decided I need to spend more time with it by dumping some oil on the garrage floor. From the hole in the water pump.



Being a low km 85 model I expect the water pump shaft will be the old style so I have a question. Has anybody cut the thread off the end and drilled and tapped it to take a bolt? I don't have it apart yet so don't yet know if the design makes this possible.

Another thought, it's leaking out of a hole big enough to fit a small finger into next to the sender, not the drain hole at the bottom of the sump??????

oh bugga !!! peter ....

i wonder if thats the hole for the temp sender on the rt models ....is it threaded ? ....(might have to clean it out with some dereaser to see properly )

Found this pic on the net. Leaking out of the hole to the right and above the 2 machined holes. The machined holes are the sender and drain I think.

pjjms wrote:Another thought, it's leaking out of a hole big enough to fit a small finger into next to the sender, not the drain hole at the bottom of the sump??????

I`ll guess your weep hole is blocked, then the oil searching other ways to get out.

Inge K.

I'll almost gaurantee you have a leak at the joint between the pump casing and the engine. The hole you speak of is where the wire for the oil pressure switch threads through and when the joint leaks oil runs around the pump casing and collects in that void space. This happened to me 3 times when I rebuilt my water/oil pump. In the end I managed to get a seal by using Loctite Master Gasket 515 and preparing the surfaces with Loctite Primer T. The manual states a 3Bond product (can't remember the number).

Remember, this joint is under full pump pressure, unlike most other joints on the engine, that's why a high pressure sealant which is not brittle is required. Don't try normal RTV silicone, it will leak, and so will Permatex (both my experience). Hope this helps.

ah ! mystery solved dennis .......good work

Dennis wrote:Don't try normal RTV silicone, it will leak, and so will Permatex.

Could be that I`m just a very lucky guy, had this problem 16 years ago.

And did try 3 or 4 different sealants (did not have the recommended one at hand),
all started to leak after some time.

The last one I did try was Permatex blue RTV, at this day the pump is still dry.

Inge K.

You were right Dennis. Took the pump off this morning, resealed and so far no leaks. Used Loctite 510.



Thanks for the help guys.



Peter

I used Loctite 5920 Premium Copper silicone on mine over a year ago, and 5000 odd miles later it is still oil tight.

Dredging up an old thread to ask "Would Permatex High Heat Red RTV possibly work to bond the pump assembly to the engine block (given Permaex Blue worked at least in Inge's case)?" Reason is I have this in the chemicals drawer in my workshop.

I have used it for that exact same job and all is well with the pump still, just be careful with the oil drain hole.

I am a bit too far from home to check my sealant draw but used a red sealant on the water pump that I think was Permatex Red. It came via a big company that used radial engines which was used to seal against oil not coolant so should be good.

Crazy Frog wrote:

This is the mine
https://drive.google.com/file/d/1bw1fmaox4J76DHogkdg0cEfus3_L906J/view
https://drive.google.com/file/d/1br03h1dA6leigGZ08kKREYGLaQ6RVYLj/view

can i reuse it?
Thanks

Zisco wrote:This is the mine
https://drive.google.com/file/d/1bw1fmaox4J76DHogkdg0cEfus3_L906J/view
https://drive.google.com/file/d/1br03h1dA6leigGZ08kKREYGLaQ6RVYLj/view

No images are being displayed in your links.

Now?
https://drive.google.com/file/d/1bw1fmaox4J76DHogkdg0cEfus3_L906J/view?usp=sharing
https://drive.google.com/file/d/1bpgBUwTbkGqDlFkHJ6fKxFMDdBuSXgyS/view?usp=sharing
https://drive.google.com/file/d/1bpetyGH0-ra4-E_FuhsfUUi_oj8NT4Uu/view?usp=sharing