K11 Owners Group

Flying Duck · Posted: Sun Jun 17, 2007 4:26 pm Post subject: Waterpump advice needed

I've never really messed with the waterpump stuff but I need to now.

On my 93 24k mile K75S engine that's been sitting for 6 or 7 years I messed up the drain hole so at a minimum I need to replace the housing. (The drain plug head was stuck and stripped - when I tried to slot it with a Dremel to remove it with an impact driver, I went a bit too deep and slotted the housing hole where the drain plug crush washer seals. DOH!

My options: (Ones I can think of anyhow)

a) Just replace the housing.

b) Replace the housing AND also the guts with a waterpump from 50k engine that was running fine a year ago. The theory behind this is that the exsiting pump assembly in engine may have "atrophied" after sitting for so many years.

c) Just fill the slot that I put in the current housing drain hole with JB Weld and cross my fingers. (Easiest option but I don't trust it to be a reliable fix.)

Note that after replacing the fuel injectors and before dropping this motor from the frame, I did succeed in getting the engine up and running and warm enough for the fan to kick in and the colling system seemed to operate normally. So I'm leaning towards option a.

Also, since I have to pull it apart, are they any seals I should replace as prevenative maintenance while I have thing opened up?
_________________
93 LT (x2)
94 RS
86-97 K75F(K75/100/1100 Frankenbrick)
86 K75C w/paralever, hi perf cams,TURBO!
91 & 92 K75Ss
91 K1
86 custom K100
14 WR250R
IBA #17739 (SS1K, BBG, 50CC)
Buy parts HERE

duckbubbles · Posted: Sun Jun 17, 2007 11:50 pm Post subject:

Duck-
You might get away with replacing the whole assembly with the "recently" used one you have. If the seals haven't given up and it doesn't leak.
One thing to consider is that the shaft that is exposed between the water pump seal and the oil pump seal is prone to rust. If you have to take it apart, it can be polished out and I have used JB weld to fill in the cavities. That shaft has the oil pump gear made on it and is pretty expensive new. Also the water pump seal is pretty expensive and is pretty easy to screw up when installing it.
Good luck.

Frank
_________________
85 K100/1100RS, 321,000 miles, 25 years
96 Ducati 900SS/SP, sold it
05 R1200ST, 35,000 miles, 5 years
400,000 BMW miles

andyc · Posted: Mon Jun 18, 2007 7:02 pm Post subject:

Never underestimate the power of JB Weld. It has patched the hole in my front brake reservoir for over a year now

Flying Duck · Posted: Mon Jun 18, 2007 8:07 pm Post subject:

Yeah, maybe I'll try the JB Weld in the slot and put some plumbing teflon tape on the drain plug threads. Not much risk as I don't plan to take the K75 on any LD trips as I've got the LT for real touring.
_________________
93 LT (x2)
94 RS
86-97 K75F(K75/100/1100 Frankenbrick)
86 K75C w/paralever, hi perf cams,TURBO!
91 & 92 K75Ss
91 K1
86 custom K100
14 WR250R
IBA #17739 (SS1K, BBG, 50CC)
Buy parts HERE

michaelcurrin · Posted: Mon Dec 10, 2007 11:50 am Post subject:

Jim · Posted: Mon Dec 10, 2007 7:57 pm Post subject: water pump

Mike - just had the water pump rebuilt last spring - the first time Anton used the new seal with the old bushing. The bushing compresses the seal somewhat and might cause the new seal to fail. The new seal is deeper than the old one - you either need to get the new bushing, or cut/grind the old bushing down.
_________________
Jim
1997 K1100LTSE 94,000 - still has gremlins!
1995 R100RT Classic 16,650 crashed - repaired!
1992 K75RTP 46,000

"We shall not all die, but we shall all be changed."

michaelcurrin · Posted: Tue Dec 18, 2007 9:46 pm Post subject:

Just got the new bushing, its about an 1/8 inch shorter than the original, so that was probably my problem, hopefully will get to sneak in a little barn time this weekend and try again.
_________________
Mike Currin
20 BMW R1250RS
93 BMW K1100RS / EML Speed 2000
06 Ducati ST3
67 Triumph 650 chopper