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1Back to top Go down    water/oil pump. Is this the right seal?? on Fri Apr 26, 2013 8:02 am

Fentible

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Busy rebuilding a spare pump to keep on the shelf. Its a cast Iron impeller and the seal was purchased quite cheaply.
Firstly the spare pump has an additional sender unit screwed into a point that is blanked off with a bolt on my original pump. No biggie just curious as to its purpose.
Now then the seal I have been supplied with as the correct part for a cast impeller pump, has a plastic cage which i will assume is purely for transportation and storage purposes.
The problem is the uppermost seal diameter seems to large for the impeller shaft. The seal through which the shaft enters is a tight fit (or will be), however the seal through which the impeller shaft exits is a larger diameter than the shaft.
I am attaching explanatory photos, but basically, have I been supplied with the wrong seal?? I though at first that the impeller itself may have a boss that fits into the seal but it doesn't. Additionally the impeller shaft appears to have two points of rubbing contact.

Impeller shaft with seal as supplied.


Here you can see that the uppermost seal is a larger diameter than the impeller shaft


As ever, advice from those who know wold be greatly appreciated.

Fent

    

RicK G

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The seal is the correct one. The sealing takes part on the 2 parts of the seal not onto the shaft. One part fits into the housing and the other clamps onto the shaft and the two parts move against each other and make a seal.
There is a later type of seal which in my opinion is far better but can't be used with that shaft. You need the later type of shaft and they are expensive. Check the part of the shaft that the oil seal runs on and if you can feel a depression with your fingernail it needs to be replaced. One other thing to be awate of is that the threaded section on those early type shafts have a habit of snapping and leaving you with an overheating engine.
If the seal area is damaged then you will need to get a new shaft as those have been superceeded by one that has a threaded hole for a bolt.
Personally I would be replacing the shaft and getting the later seal kit but that is your decision and if the oil pump seal area on the shaft is OK then it really isnt necessary and would perform well as it is.


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Bikes 1986 K100RT, 1993 K1100 LT, 1994 K1100 LT, 1993 K75 RT, 1996 K75RT, 1986 K75 GS, 1979 Z1300 Kawasaki X 2 & 1976 SR 500 Yamaha for now
    

MikeP

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The additional sender is for the optional temperature gauge.

    

Fentible

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You guys are the best!
Rick, thanks for the seal info and yes I fully appreciate that getting the modified pump parts would be the best bet but despite some marking, the seal area on the impeller shaft is unworn. Its only to keep as an emergency spare.
Mike thanks for identifying the spare sender port.

Fent

    

5Back to top Go down    As said above... on Fri Apr 26, 2013 12:09 pm

ibjman

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As said above........you'll probably end up throwing this seal & shaft away when you get it all assembled and tighten the final nit on the front of the impeller when the thread "snaps off" in your hand just as you get the idea you've got it done.
Take the advice of others that have gone before you and discard the shaft now. The metal in the end of the shaft thread is all crystalized and will indeed "dissolve" in your hand.

    

Avenger GT

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Dump the shaft, it will break, and you can't remove it without damaging the new water pump seal.

    

Fentible

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Ah.......................harbingers of doom Very Happy
You are probably right but still worth a go in my book. I promise to let you know either way.
Now can someone just tell me which way this pesky seal goes in please and what torque the end nut should be tightened to? (preferably a pre-snapping amount)

    

Avenger GT

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The one on mine didn't even get to a torque figure, barely hand tight with a small ring spanner and it snapped off. You have been warned!!! Rolling Eyes

    

Fentible

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Warning duly noted Avenger...............but which way does the seal go in??

    

ungaas

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The "U" side faces into the engine, solid flat side(with the writing) out into the pump or water side.


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Fentible

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Hi Ungaas, thanks for that however its the seal in its entirety Im unsure of. If you look at my initial photos you will see the combination of seals contained in a plastic cage which I assume is simply discarded? However once the plastic cage is removed, is this the order that the various parts are inserted into the pump? ie small end in first, ending with the large black seal face up and against which the impeller seats??
The parts diagrams Ive looked at are unclear as is the haynes manual I have which shows the later cast impeller shaft. I have read so much about the varying shafts and their counterpart seals that I'm unsure as to how this particular item should be fitted. Anyone have photos or a clear description of how these are fitted into the pump?

    

twincarb

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have you read through this


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13Back to top Go down    you only pictured 1 seal on Tue May 07, 2013 5:59 pm

ibjman

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You only pictured 1 seal, it is the water pump seal. The side with the plastic goes into the housing last or up, but only after the neoprene oil pump seal goes in to the bottom of the cavity 1st. The Oil pump seal, like all standard seals goes into the housing with the lip facing in towards the oil. By the lip side I mean the side that has a round "gator" spring wrapped around the seal surface. Peek inside under the lip you'll see it but don't disturb the spring. It keeps the lip edge of the seal wrapped tightly around the oil pump shaft until oil pressure occurs to apply pressure there.
After the oil seal is correctly seated in the bottom of the shaft bore, the water pump seal is installed next with the plastic covered proctored side up. or in last. this has to be installed very carefully to avoid: SEE INGE's NOTE about the plastic will break away upon installation (normal) SORRY INGE & THANK YOU
#1 damaging the seal
#2 disassembling the parts of the seal from around the coil spring. The coil spring is designed to hold the rotating sliding surface of the seal firmly against it's seat (slip ring) (usually a ceramic piece) & very fragile.
When you have both seals in place, you end up with a void area between them that is connected to a little drain hole in the front bottom of the oil pan. If the water or oil side seals leak, the leakage, runs down & out the drain hole without contaminating the opposite side fluid.
Once the seals are in place, the shaft is reinserted from the back side and drawn up through the center diameter of the water pump seal so the inside of that seal seals tightly around the shaft and then rotates with the shaft.
I am not familiar with the old style seal, but I believe it's rubber on the inside and will reasonably easily allow the shaft to slide through it. You may have to keep gentle pressure on the outer surface of the seal as you put the shaft through it to prevent the drag between the seal & shaft from pulling the seal apart off the coil spring. I'm just not sure.

The newer style seal is a "press fit" to the shaft and has to be drawn through the center of the seal using the bolt & 2 different spacers + the impeller to apply inward force on the seal as the shaft comes through in the outward direction.
Good luck



Last edited by ibjman on Tue May 07, 2013 9:06 pm; edited 1 time in total

    

Inge K.

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Hi Fent.

About the version of water seal you got, have a look at this and this.


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15Back to top Go down    Re: water/oil pump. Is this the right seal?? on Tue May 07, 2013 10:35 pm

Ned

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Ned

05/1986 (K55) K100RS Motorsport (Europe), Production Code: 0503, 110k km, VIN:0140519 (SOLD)
1976 Honda Goldwing GL1000 (naked)
1997 BMW K1200RS red, VIN: WB10544A1VZA22667
    

Fentible

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Thank you for leaping in all. Ned, Inge K, and twincarb for the helpful links and IBJman for the detailed explanation.
I hadn't appreciated that I was missing the oil seal, looking at it now its fairly obvious. I assumed the plastic caged item was all I needed. The cage itself also makes much more sense having read the IngeK's link to a BMW sevice notice.
In deference to all who have advised binning the impeller shaft for the later items, the sole reason Im persevering is that so far the cost of parts has been less than £5 (plus an oil seal which I will order today) And once (if) finished its simply going on the shelf as a 'get me back on the road quickly' spare. It just didn't make sense, at this stage, to incurr the cost of the modified parts. Not a case of ignoring those on this board who have the experience and knowledge.
Thank you all again
Fent

    

17Back to top Go down    We all hope on Wed May 08, 2013 12:59 pm

ibjman

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We all hope you do well. And I am hoping that you are the exception case to the "general rule" the rest of us have learned.
It's hard to express the level of disappointment that most of us felt after the stressful moments of trying to get the water pump set just right to have the shaft stud almost just "fall off" the end of the impeller with the nut still attached before the nut ever begins to feel properly tightened.
That said, it's easier to understand now your reasons for moving forward as planned. You have nothing to lose.
If you end up having to re-do, you probably could salvage the new oil seal in the housing by carefully not disturbing it when you remove the newly installed water pump seal. You will want to replace that along with the customary new shaft and additional spacers + impeller.
I think you made a good choice, being as how the pump is a spare only.. Good luck, take pictures for us along the way & keep us all posted on your progress.
Although the newer seal design is supposedly "better" the old design took a lot of K bikes a lot of trouble free miles before the newer one was developed.
Regards, ibj....

    

18Back to top Go down    By the way???? on Wed May 08, 2013 1:02 pm

ibjman

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By the way, all you coolant pump aficionados.........I have the pump off my 86K 75. Inspection reveals that it has a bolt in the end of the shaft, but still has a cast Impeller.
Can I assume it will still need an updated shaft & spacers + impeller when I rebuild it?

    

Ned

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@ibjman wrote:By the way, all you coolant pump aficionados.........I have the pump off my 86K 75. Inspection reveals that it has a bolt in the end of the shaft, but still has a cast Impeller.
Can I assume it will still need an updated shaft & spacers + impeller when I rebuild it?

My experience is that the amount of corrosion on the shaft tends to dictate things. If it is cactus new seals will not work ... you will have to get all the bits. From memory the shaft comes with the oil pump gear.


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Ned

05/1986 (K55) K100RS Motorsport (Europe), Production Code: 0503, 110k km, VIN:0140519 (SOLD)
1976 Honda Goldwing GL1000 (naked)
1997 BMW K1200RS red, VIN: WB10544A1VZA22667
    

20Back to top Go down    Re: water/oil pump. Is this the right seal?? on Wed May 08, 2013 10:04 pm

RicK G

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@ibjman wrote:By the way, all you coolant pump aficionados.........I have the pump off my 86K 75. Inspection reveals that it has a bolt in the end of the shaft, but still has a cast Impeller.
Can I assume it will still need an updated shaft & spacers + impeller when I rebuild it?
I buy just the seals and O rings then machine 3mm of the back of the boss of the impeller and all is good.


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If everything seems under control then you aint goin fast enough:- Mario Andretti
Bikes 1986 K100RT, 1993 K1100 LT, 1994 K1100 LT, 1993 K75 RT, 1996 K75RT, 1986 K75 GS, 1979 Z1300 Kawasaki X 2 & 1976 SR 500 Yamaha for now
    

ibjman

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I'm guessing this is still the old type seal without the spacers on the shaft regardless of the fact that it has a bolt rather than a nut. That is the question. What's inside this pump?
Not looking for information about what others have done to repair theirs. + few of the users here have the equipment to machine the impeller.
Thanks for your ideas.

    

22Back to top Go down    Re: water/oil pump. Is this the right seal?? on Thu May 09, 2013 12:17 am

RicK G

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Unless your shaft is damaged by rust pitting or seal lip damage then there is no need for a new shaft just seals, O rings,spacer and impeller.


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If everything seems under control then you aint goin fast enough:- Mario Andretti
Bikes 1986 K100RT, 1993 K1100 LT, 1994 K1100 LT, 1993 K75 RT, 1996 K75RT, 1986 K75 GS, 1979 Z1300 Kawasaki X 2 & 1976 SR 500 Yamaha for now
    

Fentible

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Well I know its been a while since I posted the original topic but I did say that I would come back and let the forum know how I got on with my early water/oil pump rebuild, the one with the dodgy nut.

I've been busy with a non BMW rebuild now finished and out the garage door so I can once again turn my attention to the K100.

I got around to finally rebuilding the spare pump, fiddliest bit was definitely retrieving the bits of plastic that broke off the water seal installation cage into the chamber................I got to seven pieces (there are 8 ). After scrabbling around the floor, bench and fishing around the interior of the pump with bits of wire, I eventually discovered the final piece resting between the laces of my right shoe.

The most nerve wracking bit was tightening the centre nut to the specified 21 newton metres, I only breathed out after the torque wrench signalled the achievement. Given a few people have experienced the threaded portion of the shaft shearing off at this point, I guess I've been lucky.



   

    

charlie99

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yay !...nice result .


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BIG D

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Cool 

Well done, this forum is the best tool in the toolbox.  Very Happy 

BIG D

    

richarde1605

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As an aside about the groove worn in the shaft. On my now 'spare' K100RS I brazed the groove up and skimmed it on a lathe then polished and crosshatched it, still fine 40,000km later..


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Fentible

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Thanks all and I agree Big D I'd definitely have messed the new seals up without advice from the good people on this forum.
 
Richarde that's a fairly high tech approach, wish I had the skills and the tools.

Next bit is removing the TB's for a clean up...................another topic post imminent.

Fent

    

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