Water pump seal leaking for the 2nd time

[F14CRAZY]

Last weekend I attempted resealing my water oil pump due to oil from the weep hole.

I did this:

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

Also watched this:



Fixed the oil leak. Made coolant drip instead. Wasn't dripping enough to stop me so I rode it all week anyway, topping up the coolant every other day.

Ordered a new O ring, water seal, and oil seal from the dealer. Resealed the pump AGIAN today.

Now the coolant is dripping more than ever. I think at highway speeds it would be more like a trickle than a drip.

I don't know where the hell I messed up in it. I DID NOT force the shaft through and only pulled it through with a bolt and against the front face of the water pump seal as the instructions describe. Made sure everything was clean and free of any old seal. I felt my shaft wasn't really corroded but for the 2nd time I hit it with some emery cloth.

Seems BMW doesn't offer a new pump specified for the K75 anymore but the K1200LT calls for the same housing and other parts so I assume that would work but that $484 I don't really want to spend, especially after dumping like $150 into seals and other parts into mine.

What should I do? Can I go to an industrial supply house and get a conventional seal to use in place of the stupid BMW seal?

[Elipten]

Lord you are having a bad experience.  I think when my time comes it will go to the dealer. What a crummy way for a good K75 to die.

[Motorhobo]

There was a thread a while back about someone using JBWeld or 2part epoxy or something like that to fill pits in the impeller shaft and then sanding it smooth...did you do a search here on the forum for water pump issues?

Btw I had some coolant leaking from around the housing cover when I bought the red brick -- I pulled the cover and resealed it with black RTV and no more leak. Are you sure he leak is coming from an internal seal and not just the cover? Leaky cover will give you pure coolant...I thought a bad seal would give you more of an oil/coolant mix as the two types of fluid intermingle due to the bad internal seal. But maybe I'm wrong about that.

At any rate, long story short -- for me the coolant leak was due to original OEM silicon sealant failing after 20 years. I remember 10 years back, back when I was having the black brick dealer serviced, I had the water pump replaced due to some leak to the tune of $500 or more, and it wouldn't surprise me it if was just the cover sealant bAck then too.

[Scott_]

There are 2 separate seals(water side/oil side) with an air gap between them(where the weep hole is).
So it would be entirely feasible to have a leak at the weep hole that is either only oil or only water, or both could be leaking and give you both.....

[F14CRAZY]

From my research it seems hit and miss as to whether a dealer would be willing to put new seals in your pump. I've considered asking them that.

I'm very certain the leak is internal and from the seal as it's coming from the weep hole.

As I mentioned my shaft has a tiny bit of pitting but I don't understand how this would affect the seal. Is the pitting tearing up the "blue goo" inside of the seal as the shaft is being pulling into it? It isn't like an oil seal where the pits would be riding on the lips of the seal. I have thought about using JB Weld or something like that to fill them.

I don't think I'm having a gasket issue. I made sure to get both the block and pump surfaces super clean (scraped of old RTV and scrubbed with brake cleaner) and used Permatex The Right Stuff (automotive assembly line stuff with zero wait time).

The online parts catalog doesn't like a complete assembly for the K75 anymore but K1200's have one listed for $484. I'm a full time college student and $484 is not possible right now. The housing, seals, and impeller all share the same part numbers with the K75. Only thing I can see are that the oil pump gears have a different number of teeth. Therefore, to avoid the problems and take the easy way out, I ordered a used '99 K1200LT pump assembly from ebay and the oil pump gear for a total of $96. I figure I don't have much to lose as this point. Will give an update when they arrive and I get them on.

[Scott_]

F14, I feel your frustration with this. I've worked with similar mechanical water pump seals in industrial pumps and they can be very finicky to install properly.
Cleanliness is extremely important with the ceramic face between the 2 parts of the water seal. I've had them leak from just a finger print on the face......

[F14CRAZY]

It is frustrating...not that it's the same but I don't think I spent over $15 or over half an hour last year when my fiancee's Chevy Corsica had a leaking water pump...

[orforester]

I am going to bet it is you impeller shaft, if it has any pits it will leak.  I know it is not what you want to hear, but new impeller might be in order.  Remember the water/oil is under a lot of pressure and everything needs to be clean a fit tight! 

I also had one leak after a fix and it turned out to be the seal to motor, cleaned it back up and re-sealed it, waited for 15 minutes then applied the torque to it, sealed right up.  I would try re-seal first, but if it was good seal I bet impeller, which is a bummer as you need new seals to match the impeller.  Sorry!

[TimTyler]

Any mistake while repairing the pump is an expensive mistake.

Overhauling my pump was the only K75 service I've ever had done at a shop.

My old, worn rotor sits on the shelf next to my desk

[F14CRAZY]

Does anyone have any experience with bolting up a K1100 or K1200 water pump to a classic K?

[F14CRAZY]

The water/oil pump arrived today. I've been busy with college stuff and it was actually snowing outside, so I haven't gotten to installing it but I will in the next few days. I did find an old thread here in which a K1200 pump was definitely fitted to a K75 fine, though if I remember right it said I have to use the K75 water pump cover. I'll post back with my findings.

I guess picking this up for $96 wasn't bad, counting that it holds up for a little while at least. I didn't post but my temperature sensor broke (for the temperature gauge mounted in the fairing) when I put the water pump back together the first time and it seems those sensors are over $40. And this K1200 pump came with the sensor (and oil sensor)

[F14CRAZY]

Got the K1200LT pump put on today and went for a spin...no more leaking. Nice being back in the saddle after a week of downtime. I suspect there's still some seeping of oil from the timing chain cover and the pan but I'll deal with resealing all that in the off season or something.

No history came with the used pump but I hope it'll last at least a while to make it worth my effort to skip around the issue of resealing mine. I've kept the old one in case I end up having to do that though.

[Motorhobo]

Good info about the K1200 pump -- thanks and glad your back on two wheels.

[Gumbo]

  Digging this Up...  F14 couple of questions,  Is the k1200Lt water/oil Pump still Going?  If not how long did it last?  Thanks for any info on this Installation ..

[bizzaro]

Got the K1200LT pump put on today and went for a spin...no more leaking. Nice being back in the saddle after a week of downtime. I suspect there's still some seeping of oil from the timing chain cover and the pan but I'll deal with resealing all that in the off season or something.

No history came with the used pump but I hope it'll last at least a while to make it worth my effort to skip around the issue of resealing mine. I've kept the old one in case I end up having to do that though.

 :2thumbup: :clap: Glad to hear you got it resolved.  When I first got my K11 it was leaking oil at the pump.  P O didn't use any  sealant.  :twak:   I took it apart and used Permatex Ultra Black which my local BMW dealer recommended.  Followed the directions for the Ultra Black and I haven't had a drop o oil or coolant since.  I think directions said to lightly torque it till some of it squeezed out. Let it set over night, then give it the recommended torque.   :2thumbup: Good to know that 1200 pumps are the same as, I guess, all K bikes?

[F14CRAZY]

Pushing 40k miles on the used K1200LT pump and no leaks!

It seems that if you use the K1200 gear it should fit an longitudinal K bike.

For RTV I just use Permatex The Right Stuff. I've got like half a gallon worth of Ultra Black but there's no guessing with The Right Stuff...install, refill and return to service immediately

[Gumbo]

  Exactly what I did,  only My original oil gear drive is 19 tooth count like the k1200Lt pump so everything lined up perfectly and No More Leaks!!  Thanks F14 for the Original Post.....Gumbo. :2thumbup: