fork seals 91 k100rs

[Kevin L.]

One fork seal is leaking badly. The schematic diagram in the haynes manual looks much more complex than the old airheads.
 Wondered if anyone had experience to relate before I get into it.  Are there more parts to replace than just seals ? :yow
 

[Laitch]

You haven't followed up on your power to the fuel pump thread. What was the outcome?

[Laitch]

Wondered if anyone had experience to relate before I get into it.

I had a guy point a pistol at my head when I told him he had to rest in the shade for 10 minutes after having worked two hours hand digging holes through asphalt for tree planting in 90ºF/90% humidity.
 :grimreaper:

[Martin]

Seals can sometimes benefit from cleaning. A device called a Seal Mate can be bought or made from a soft drink bottle (soda bottle). There are also a couple of methods of extending the life of your seals. You can fit fork boots, or you can fill the gap between the seals and the dust covers with heavy silicone grease. Clean and change the grease at least every twelve months more often when riding in dirty conditions.
Regards Martin.

[Kevin L.]

You haven't followed up on your power to the fuel pump thread. What was the outcome?

     


Well, as you may recall the fuel pump issue came up on reassembly after a clutch and spline lube ; completely unrelated. At the end of my rope I sent it in to my dealer where it sat for two weeks of course but took only three hours work to solve the problem ; but not find it.  The young mechanic couldn't give me a specific cause for the malfunction, said:" I don't know man, I just ran checks on each related circuit and it started and ran great". That was 800 miles 60 days ago.

[Laitch]

Well, as you may recall . . .

I can't recall much. I usually need to find the thing and read it again. Anyway, if you could go back to that thread and finish it off with that mechanic's inspiring words, it might help the next reader realize that there is yet another option for repair—divine intervention.

[Inge K.]

  Are there more parts to replace than just seals ?

The parts needed when doing a overhaul on this fork is the same as the K11 models.
Have a look here.

[Kevin L.]

   Thank you , I had planned on gaiters too.

[bizzaro]

Seals can sometimes benefit from cleaning. A device called a Seal Mate can be bought or made from a soft drink bottle (soda bottle).

I find the seal mate trick, whether bought or home-made, to merely slow down the leaking, and a temporary solution to postpone the inevitable replacement at best.  Mine are due! YMMV


And I was wondering if anyone who is experienced in this area could/would recomend one of the many after Market seal and dust cap replacements(a bunch on fleabay).  Or is it best to go OEM here. Also, what are a good quality fork gaiter? If I am going through the trouble of installing them, I don't  want ill fitting or cheap gaiters that will harden and disintegrate prematurely.

[The Mighty Gryphon]

I would go to a bearing/seal place and get what matches what is in the fork.

As far as gaiters, the Rancho 1952 is pretty highly regarded.  They fit good, keep the crap out, and are reasonably priced compared to what is out there.   I have them on my bikes and they have held up pretty well.   

https://www.summitracing.com/parts/ran-rs1952

[Laitch]

High quality BMW /5 boots can be had from MAXBMW, among others, at a price from $24 to $35 each. I installed Rancho RS1952 boots on my bike. $16 for a pair of them.

The bottom segment of a Rancho boot has a slashed opening on opposite sides. Some folks have considered that as an air passage to help compression and extension of the boot; some think it is a weep hole to help indicate a seal leak. The OEMs don't have that. There's one roll pin in a pleat of each OEM boot that acts as the air passage.

I cut my Rancho fork boots right along the center of a valley pleat above the slashed segment to remove it then I stretched the boot over the fork slider and secured it with a clamp. I also installed one roll pin in a pleat of each boot facing it to the rear and secured it with a micro-dab of rubber cement. The boots have been installed for three years and are holding up well. I've read some riders claim their OEM /5 boots have lasted twenty years and look like new. Well, gollee!

[bizzaro]

Thanks Gryph.
 I thought Summit Racing had them.(gaiters) The search engine there is not the best. Thanks for the review.  I would rather pay more up front and be done with it, but don't need to be throwing money away. Sounds like the Rancho 1952 will do the trick. (Summit also carry the NGK DR7EB for anyone looking. Not as cheap as O'Reillys, but in stock for $2.97 each) 

Laitch.  So you didn't care for the slit  to weep moisture/air release? How big is the slit!? You redesigned it to your liking? And having it just a bit shorter,once you cut out the slit, is it still plenty long enough that it is not stretched a bit end to end. I don't quite get how the roll pin works?? I may, if I cut out the slit, just use a small hole punch on the bottom of one of the lower pleats?

[The Mighty Gryphon]

I put a couple 1/8" holes at the top of my gaiters where they were up under the fairing to help let the air out.  Not sure if they were really necessary.  I used a piece of brass tubing from the hobby shop as a punch to make the holes.  A lot cheaper than a real punch.   

[Laitch]

So you didn't care for the slit  to weep moisture/air release? You redesigned it to your liking? And having it just a bit shorter,once you cut out the slit, is it still plenty long enough that it is not stretched a bit end to end. I don't quite get how the roll pin works?? I may, if I cut out the slit, just use a small hole punch on the bottom of one of the lower pleats?

Think of the roll pin's purpose the same as the soda straw you use to breathe when you submerge yourself in the bathtub pretending to be an orca, Biz—air circulation.  It also probably limits condensation and allows the bellows to compress without inflating—if such a circumstance is even possible.

I follow BMW's purported design—I haven't actually seen it but I have faith that Snowbum described it accurately. There's plenty of length for the bellows. In fact, the bellows could be a couple of inches shorter and the tube above it could be used to mount auxiliary lights or promotional signs.  :yes The hole doesn't need to be large. A few millimeters should do it. I've had no problems with it anyway.

[bizzaro]

Yea, I get the straw part.  Just where exactly is the roll pin placed to improve the products function? And how is it an improvement from an engineering standpoint. I mean a hole with a stainless steel eye rivet maybe, but a roll pin?  Maybe if I see one it will explain its-self to me.  And if it can't explain I will understand that it is a way for BMW to charge an extra $$$$$$$$ for a part that cost a couple o bucks to make!

[Laitch]

The fork boot pleats are like those of a bellows. Pleats have peaks—the folds facing outwards, and valleys—the folds facing inwards. I chose a valley above the slitted section and cut along its fold to the remove the slitted section. I then stretched the boot over the slider and clamped it. It's a tight fit for a standard hose clamp. An oetiker  clamp, smooth band screw clamp or even a stainless steel grip tie might be be a better fit. In any case, the work isn't as laborious as picking watermelons.

The arrow in the photo indicates a valley.  The slit was obtrusive to my refined style sensibility so this is how I met my needs. Of course, the hose clamp lowers the tone. :giggles

Regarding your questions about engineering and cost: I don't give a damn about those factors. I don't allow science or economics to interfere with my fun. The roll pin is BMW's way of insuring the hole remains open to perform its putative function.

The roll pin is positioned on the rear side of the boot.

 

[bizzaro]

Yes, I get it.  The boots look plenty long enough for sure..............and yea, even black zip ties would be snazzier!(or at least less visible)........................I guess if the roll pin protrudes out a bit with the slit of the pin down, it may help to keep dirt and moisture from entering, and mostly let air and moisture exit as intended. 

Man I got so much stuff I want to do to my bike...........Some critical, some advisable, and some just fluff!................But ya know, it started right up when I took it out of storage last Thursday! Ran without a hitch. (other than a sticky side stand switch that I temporarily forgot about) So now I patiently wait for the next reasonably warm day to ride, and begin a new season. :riding: :riding: