The wife and I took the k100rt on her maiden journey yesterday,125 miles,on the way home the water pump went completely out. The fan came on and stayed on, as I pulled it into the garage,it was indicating that is was getting hot on the way home,by the temp light, came on and went out. The engine didn't seem overly hot, so I went on home.
I drained the coolant this morning, hardly any in it, pulled the water/oil pumps off, the seal looked to be the original ones possibly, very hard to get them out of the recess they were in. Going to get the seals and o-rings tomorrow and put it back together. Will know more when I get it running again, may do a compression test to see if it's ok, probably after I take it for a ride to see how it acts. The oil that came out of the bottom end was clean looking, didn't show any signs of darkening.

I sure hope it's not damaged any. I noticed a little oil coming out of the pump area before the ride,and was thinking it was time to pull the pumps off and rebuild.

Anyone that has any prognosis on this condition as to the likelyhood of engine damage please share it with me, thanks, bob.

Aside from the temp light going on, any other indications that the motor was overheating? Knocking, poor performance etc?

when I pulled it into the garage I felt the head, didn't feel hot like I would of thought it should if it was over heated. It started right up this morning with no bad sounds. It ran just find coming home, maybe it will be ok. I would think if it got hot enough to warp the head that the oil would have gotten darker in color.

I realized why the temp light didn't come back on, it had no water around the sending unit, or atleast that's what I'm thinking. I should have the parts tomorrow to get it back together, may get it back together before I go to work a 2pm, if not the next day for sure. thanks

If the temp light went off quickly after the fan came on, I wouldn't expect any of damage. The fan did the job.
My concern is having next to no coolant in the radiator.
If the seal got destroyed and the coolant escaped on the drain hole, you are safe. If not, the coolant may have been mixed with the oil. A good indication would be a raising level of oil or the oil turning into a white creamy substance.

The oil looked normal in the sight window, I blocked the center stand up and put a couple of inches of blocks under the front wheel to reduce oil leak when pulling the pumps, I watched the oil level drop when I pulled the pumps and it looked normal. Think I'll drain the oil before restart to see if there's any coolant in there.

nodrtbike wrote:The oil looked normal in the sight window, I blocked the center stand up and put a couple of inches of blocks under the front wheel to reduce oil leak when pulling the pumps, I watched the oil level drop when I pulled the pumps and it looked normal. Think I'll drain the oil before restart to see if there's any coolant in there.

I hope that all is well.

I have two extra temperature gauges (electronic) installed. One is at the radiator output and the other on the outside of the sump, between the fins against the sump bottom. Both will warn me that things are not well well before the overheat light comes on.

The reason I do this is to keep an eye on the oil temperature because I had a dicky slow spinning radiator fan. In Sydney, in summer this is a good precaution.

On a few occasions when the overheat light did come on, my eye was on the oil temp because this, in my opinion, reflects the temperature of the internals more accurately than water at the head output. If the oil temp went over 90C, I would pull up and give her a rest. Thankfully it never happen. Also, I tend to run 10w-60 just in case.

Saying all of the above, no coolant in the system is not good, but with a bit of luck I think that all is well. Good luck.

Will see soon enough, hope your right, thanks.

Road the old Harley over to Holt BMW and Had Marvin order the parts to rebuild the pumps. Will get the parts in the morning Hopefully. Got the parts cleaned up and ready for assembly. thanks bob

Let's hope your local BMW shop knew about the updated parts for the water/oil pump sealing area on all early K series. Refer to BMW service bulletin 11 001 02 (002) for the newest info on these updated parts.

Here's a link to that important information:

http://hrsbstaff.ednet.ns.ca/bvogel/K100/download/K100-service-bulletins-and%20special-tools/bulletins.htm

Click on your model and glide down the list to the correct bulletin number. There is an updated impeller and seal set. Retro-fitment to early K-s is not possible without the complete set of parts, unless an update has been performed already. A good spare parts man will have known about this. In our workshop we often had to machine the old pump to allow the new parts to properly fit. Once done all is golden.

Two Wheels Better wrote:.... Retro-fitment to early K-s is not possible without the complete set of parts, unless an update has been performed already. A good spare parts man will have known about this. In our workshop we often had to machine the old pump to allow the new parts to properly fit. Once done all is golden.

I am contemplating this now. Do you mean that I may have to get a new or machine my shaft? I have a 1986RS.
I was under impression that the conversion to the new impeller was optional. You just replace seals and omit the spacer, reinstall the old impeller and you are done. Correct?

I don't believe that you can get the old parts anymore.
The conversion doesn't require any machining.
Here is a good tutorial for you

Bert

I have a new question, based on c-frogs posted tutorial it looks like I will have to call my parts guy and have him order the new type impeller, the one in my pump is the cast type. Does that sound correct? Unless of course some miracle occurs and the seals are the old style which I've gathered are unobtanium.

My impellar shaft has a threaded end for a nylock nut. Not sure from the quick look at the tutorial if the new style impellar has shoulders for the shaft or a tight fit like my old shaft and impellar.

I really appreciate the tech help from all of you, thank you, bob

looks like from the tutorial that because of the new type seal the gear shaft MUST be pulled in with the threaded rod??? I'm assuming the old style shaft must of slipped in ??? because my shaft has a male threaded end, unless of course some sort of male ended tool with a female threaded end was used as a tool to pull the old style shaft through the seals???

I got the service bulletin number and the parts numbers that you posted, will run them by marvin tomorrow.
thanks

went and picked up the parts this morning, Marvin had the new impellar,spacer, and the new type seals. Put it back together before work, will let it set over night so the sealant can set up good, will put the coolant back in tomorrow and take it for a ride. Will let you all know if there's any damage to the engine tomorrow, thanks bob.

I'm going with 2 thumbs up. I think you've dodged a bullet here.

Put the anti-freeze in the rt this morning, started her up and let her idle up a little, no leaks,rode down the ridge road a couple of miles, started to rain, went back to the garage. Drained the oil, looks normal, put fresh oil in, started and let her run some more. Will be positively sure after a longer ride... although I'm pretty sure I "dodged the bullet" this time. I could not detect any difference's in the way she runs.

Thanks for the encouragement and help, Bob.

Just like Neo in "The Matrix"...

You should change the title of your post to "I was concerned"

and thanks c-frog... by weekend I expect to be " I was concerned".