My oil/water pump unit seems fairly quiet, but using a screwdriver to " listen in" then there is a fairly high pitched scream going on, presumably from the bearings.If I stand next to bike I can hear nothing except the normal "K" sounds. There is no vibration from the unit.
 I have no leaks, but can assume at some point I need to overhaul the unit . 
Do these units suffer from sudden implosion, or can I expect it to carry on long enough for a  winter rebuild. 
Also motorworks do an exchange unit., do these just bolt on or does the problem of sealing the unit still have to be dealt with. 
Thanks for any replies
Bob

audibob wrote:...motorworks do an exchange unit...Bob

My recently returned to the road K75 had started to leave a tell-tale stain on the floor. So I ordered a seal kit for it, which because of the bikes age needed a new impellor too, however after going down that route it seems my '85 had an earlier style gear shaft with a nut and that broke when being dismantled, as per mechanic doing the repair. So I have had to order a new shaft, as well.....   

If I had been more aware of the problem with the shaft I'd probably have been inclined to swap for the exchange unit; but  I am already down the road of repairing   .

It's also obviously repairable as others have done it on here and I am hopeful that the engineer/mechanic doing the repair is more skilled than I would be, and is able to reassemble and repair my pump with the kit, impeller and gear shaft some very informative posts about it. And Motoworks obviously repair the pumps, so it must be possible.... :pale: 

The exchange unit seems more costly but not hugely so. Do they offer a gtee   

The exchange route seems less fraught or less risky; and maybe simpler in the long run. 

Mark

Hi mark, 
Motorworks do not mention any guarantee with their recon pumps.
Would be interesting to value all the renewable items necessary to do a complete overhaul, against the Motorworks price. 
The inherent problem of having a combined water and oil supply casting, coupled with an exact procedure to seal the unit, means it would be negative to do just a bearing change.
Guess I need to "listen " to the pump every month, now where is my "noise-o-meter"?
Ah well, added it to my never ending list.
Bob

They dont have any replaceable bearings in then, the shaft runs directly into the alloy housing. Most oil pumps I have dealt with are the same.

It is unusual to get a K75 with a nut on the impeller AFAIK they all came with the updated shaft with a bolt, it could have been swaped out for a working early pump some years ago.

They do suffer from a sudden failure and will most often fill the radiator with oil or occasionally the sump with coolant.

Thanks for that Rick.
Looking at a diagram of the unit, I presume one part of the  ceramic seal is driven whilst seating against a static side in the housing, hence my thinking it is a bearing type noise. If you listen with a screwdriver to your housing, do you hear the same? would be interesting to know.
I think the list of jobs done to my bike at its last service was just a list. They were not actually done, ie, final drive splines, steering bearings,water/oil pump noisy??, I didnt pay over the top for her, and it does give me the chance to " get to know her" mechanically, which is always a good thing. My first LT had full BM history so i never got to do anything other than fluids and filters etc.
Thanks 
Bob