WTB K75S Water Pump Unit

[KJM00]

Like the post Subject, having issues sourcing this from OEM BMW. Looking to see if anyone has a lead on a new pump or is selling a pump lightly used for a decent price.

Part#11517676371


Thanks!

[Laitch]

If the case isn't cracked, replacement of worn parts is possible. Many here have done that.

[Past-my-Prime]

Try EME. My order details are below, fixed my water pump leakage very well. take your time and follow directions to avoid doing it twice!!

Order Details:

Code   Item   Qty   Price   Grand Total
KPUMPIMP-173   Water Pump Impeller for BMW K Bikes; 11 41 1 461 173 / BMW  1   $17.99   $17.99
PumpKit870   Oil & Water Pump Repair Kit - BMW K Bike; 11 41 1 741 870 / EnDuraLast  1   $39.99   $39.99
^ KPump-ORing328   Water Pump ORing - BMW K Bike; 11 41 1 460 328 / EnDuraLast  1   $0.00   $0.00
^ KPump-ORing392   Water Pump ORing - BMW K Bike; 11 11 1 460 392 / EnDuraLast  1   $0.00   $0.00
^ KPumpBush902   Water Pump Bush - BMW K Bike; 11 51 1 464 902 / EnDuraLast  1   $0.00   $0.00
^ KPumpSeal329   Water Pump Seal - BMW K Bike; 11 41 1 460 329 / EnDuraLast  1   $0.00   $0.00
^ KPumpSeal870   Water Pump Seal - BMW K Bike; 11 41 1 741 870 / EnDuraLast  1   $0.00   $0.00
PumpKitTool628   Oil & Water Pump Press Tool - BMW K Bike; 83 30 0 401 628 / EnDuraLast  1   $18.00   $18.00
OF-Oring425   ORing for Oil Filter Cover - BMW K & R; 11 13 1 460 425 / EnDuraLast  2   $1.75   $3.50
 
    Subtotal:   $79.48
    Tax:   $0.00
    Shipping & Handling Cost:   $30.93
    Grand Total:   $110.41

[KJM00]

My issue is coolant getting dumped directly into my engine at a very rapid pace. next steps are to completely take apart my pump and try to see what's going on but I'm sure at minimum the seals are rotted out. I'll research and look at potentially going down the avenue that you did for the rebuild. I imagine my pump is fully functional, but the reverse polarity is likely due to rotten seals

[Laitch]

My issue is coolant getting dumped directly into my engine at a very rapid pace.

Directly into your engine? You can see coolant in your engine oil?

[KJM00]

Yeah tons! Like practically real time as it goes in the radiator it goes into the block. I've pulled my pump and I was going to follow the reseal step-by-step as the pump itself looks good. But god damn i cannot get the impeller to pop off.  Got my Allen Wrench on one side and my 13mm on the other but the damn bastard wont disconnect X.x.  Taking a break before i hurt it or myself by accident.  Ordering the seal replacements as suggested above.

[KJM00]

Looks like that's why the kit recommends you buy a tool to do this part   

[frankenduck]

Yeah tons! Like practically real time as it goes in the radiator it goes into the block. I've pulled my pump and I was going to follow the reseal step-by-step as the pump itself looks good. But god damn i cannot get the impeller to pop off.  Got my Allen Wrench on one side and my 13mm on the other but the damn bastard wont disconnect X.x.  Taking a break before i hurt it or myself by accident.  Ordering the seal replacements as suggested above.

Temporarily put the pump back on the motor to loosen the impeller bolt. I've learned from experience that it's easiest to break the impeller bolt free with the pump still on the bike. (And use a 6-point socket.)

[KJM00]

Temporarily put the pump back on the motor to loosen the impeller bolt. I've learned from experience that it's easiest to break the impeller bolt free with the pump still on the bike.

I'll give it a go, thank you!

[Laitch]

Usually when a combo pump leaks, oil or coolant flows from the weep hole at the clutch-side bottom of the pump. Was fluid pooling on the floor beneath the Brick during this event? Your problem could also be a faulty head gasket.

Concerning your current trials and tribulations and in consideration of frankenduck's suggestion, heat the impeller nut or bolt, apply Liquid Wrench, tap on the fastener head, take a ten-minute break then try again.

[frankenduck]

Concerning your current trials and tribulations and in consideration of frankenduck's suggestion, heat the impeller nut or bolt, apply Liquid Wrench, tap on the fastener head, take a ten-minute break then try again.

Not necessary in my experience. With the pump still installed you essentially have the whole motor holding the shaft in place when you loosen the impeller bolt.

[KJM00]

First off you guys rule.  The engine block + the wrenching did the trick (wasted 45 minutes!) I actually took this into a shop and had them verify it wasn't the case being cracked(extensively tested and we're all clear, but the water pump rebuild im on my own for.  Looks like I'll need to buy a new shaft, and god damn these seals were in bad shape!

You rule Frankenduck and Laitch

[KJM00]

W00f! Turns out that shaft is 200 dollars, but reading the EME instructions if it's as worn as it is; recommended to replace. :'(

[Laitch]

Not necessary in my experience. With the pump still installed you essentially have the whole motor holding the shaft in place when you loosen the impeller bolt.

In my experience, I'm not put off by a minor procedure like the one I recommended. When it comes to seized fasteners, I do the seemingly unnecessary first because it allows me to relax, catch up on correspondence and finish the project sooner than waiting to do the unnecessary after it becomes necessary. 

[The Mighty Gryphon]

That nasty looking shaft is a valuable($200) lesson in the importance of changing your coolant every couple of years. 

[KJM00]

That nasty looking shaft is a valuable($200) lesson in the importance of changing your coolant every couple of years.

To be faaaiiiirr, I've purged my fluid every year  and completely flushed the system when I purchased the bike almost 6 years ago.  But to also 6 years is a blip in the 30 years span of the bike.  Having said all that, I flushed it and discovered quite a bit of sludge in my flush, If i were a smarter man I'd have seen all this coming.

[Past-my-Prime]

My pump shaft didn't look quite that bad but I wanted to get out riding so I just fine-sanded it until it shone like new.

Like you, I was astonished at the price for a piece of steel.

If you buy the kit, I'd recommend splurge and get the tool to re-seat the seals. It's less expensive and less time than doing the job twice which I hear isn't uncommon.

When you do the job, take your time; I found it to be quite finicky

[frankenduck]

If you buy the kit, I'd recommend splurge and get the tool to re-seat the seals. It's less expensive and less time than doing the job twice which I hear isn't uncommon.

You don't need a special tool to drive in the seals, you can just use sockets for that.

Here are my notes from repairing the seals 10 years ago on my 93 LT and it's still running just fine.

http://www.kbikeparts.com/classickbikes.com/ckb.tech/0.ckb.tech.files/K1100LT.Water.Pump.V1.2_compressed.pdf

[stokester]

I've rebuilt the water pumps on my two K75Ss.  A very common but not difficult procedure.

The first one took two tries before I found out that the new style seal requires the bushing be replaced.  Duck's list includes it and Max BMW now highlights it as necessary with the new slip ring seal.  I posted on the forum about it.

Internet BMW Riders site has some good info with pictures.  https://ibmwr.org/index.php/2003/05/01/water-oil-pump-rebuild/
I see the shaft is now about $250 

[frankenduck]

Shaft is about $170 shipped from tills.de or motobins

[frankenduck]

Nice used shaft on Ebay. I'd make an offer of $40.

https://www.ebay.com/itm/354110071383

(I am not affiliated with the seller.)

[KJM00]

You don't need a special tool to drive in the seals, you can just use sockets for that.

Here are my notes from repairing the seals 10 years ago on my 93 LT and it's still running just fine.

http://www.kbikeparts.com/classickbikes.com/ckb.tech/0.ckb.tech.files/K1100LT.Water.Pump.V1.2_compressed.pdf

what kind of grease did you use? I have some white lithium laying around but was just curious. did you also something as a seal when you reapplied the faceplate and everything else? about the only thing I presently have is RTV for that

[frankenduck]

what kind of grease did you use? I have some white lithium laying around but was just curious. did you also something as a seal when you reapplied the faceplate and everything else? about the only thing I presently have is RTV for that

It was 10 years ago so I don't remember. I probably used white lithium grease though.

Permatex Form-a-Gasket No. 2

[KJM00]

It was 10 years ago so I don't remember. I probably used white lithium grease though.

Permatex Form-a-Gasket No. 2

thank you very much sir. greatly appreciate it. last question. hopefully, if you were to flush out engine after it had a fair amount antifreeze and water. how would you go about that? a lower quality oil purge?

[frankenduck]

thank you very much sir. greatly appreciate it. last question. hopefully, if you were to flush out engine after it had a fair amount antifreeze and water. how would you go about that? a lower quality oil purge?

I've done a few water pumps and never worried about that but if you want to do an oil flush for peace of mind then yeah, just cycle some cheap dino oil through it.

Did you run the bike before you drained the oil?  If the oil had been sitting for a while before the oil drain then most of the water/antifreeze should've settled at the bottom of the sump and drained first since that has a higher specific gravity than motor oil.