[mprentice]

Finished up a race last weekend, rolled my sons CRF250R into the trailer...low and behold, the fork legs were dripping with oil. This is the third set of fork seals in less than a year. I think I have an idea what might be happening, tell me if this is possible.

Two weeks ago, I replaced the fork seals, and replaced the oil in the dampener AND the outer chamber. When I was disassembling the dampener, I noticed the left dampener rod would not fully extend out on it own, when compressed. I changed, bled the unit per the manual, after which it extended like it should. I reassembled everything, new seals (carefully & properly installed) and everything worked great. Like butter.....

Two weeks later, another race weekend, and it's leaking again...

I'm wondering....if that inner chamber is leaking oil and it's moving into the outer chamber, would it be a possibility that the seals are leaking because too much oil is accumulating in the outer chamber, and when the pressure builds it's passing oil through the seals????

Would this be a cause of this constant leaking in my left fork?? I can't find any nicks...and I know I'm not tearing the seals when installing (using my seal bullet and lots of grease)

Ideas?

[krisrtch]

I had issues on my CR250 leaking constantly the inner chamber seal needed replacing and all the bushing were wore out. that seal is a littel bitty sucka. jsut a thought Or Bobby Williams in Lakeland with Pro-Action is a top knotch suspension guy he did all my bikes when I lived down there in Fl.

[crfsonly]

you might want to use the Pivot Works rebuild kit to replace all the wear items as mentioned above.

ken

[riddler9]

Sounds like it is the inner, but another thing to check is look at the inside of the pipe slider when it is disassembled. I had a very small dent that caused a leak that was easily noticed by looking inside the slider, but barely noticeable from the outside unless you knew where to look and had the right light.

If the fork is still assembled, then you can wipe the pipe clean and compress it. If you have something on the slider that is causing the leak it will leave a spot of oil right over it.

I hate the seal bullet. Stretches the seal more than is needed in my opinion. A buddy had me cut the zipper off a zip-lock sandwich bag and use the bag instead. The guy that wrote the CRFsOnly how-to uses a bag as well.

[mappsterr]

Not to highjack your thread, but with all of the available technology today, it seems to me that someone would introduce an updated or maybe a different suspension system that would solve the problem of leaking seals. Not sure what that would be, but it can be a constant problem in the mud. Keeping the dust seals cleaned out helps but does not solve the issue.

[kicken]

A good tip a friend of mine uses...
before fitting the dust seal in the bottom of the outer chamber, you can insert some Oil Proof foam/sponge between the oil seal and the dust seal, then close it up with the dust seal.
This stops dirt from passing the dust seal and damaging the oil seal (much like the neoprene seal savers). He's never had a leaking seal since using this method.

He also mentioned to pre-soak the foam in engine oil (not fork oil) for some reason. Anyway, I'm currently working on my seals at the moment and might chase him up on it when I'm ready to assemble tomorrow.

[mappsterr]

A good tip a friend of mine uses...
before fitting the dust seal in the bottom of the outer chamber, you can insert some Oil Proof foam/sponge between the oil seal and the dust seal, then close it up with the dust seal.
This stops dirt from passing the dust seal and damaging the oil seal (much like the neoprene seal savers). He's never had a leaking seal since using this method.

He also mentioned to pre-soak the foam in engine oil (not fork oil) for some reason. Anyway, I'm currently working on my seals at the moment and might chase him up on it when I'm ready to assemble tomorrow.

I like the sound of that. I would imagine that it would be a very small piece of foam?
Oil proof foam? Is this what you are talking about? http://www.alibaba.com/product-gs/52036 ... Sheet.html

[kicken]

Foam is cut to 10mm thick X 10mm wide X 160mm long.

Here is a snip-it from Page 123 in the Australasian Dirtbike Magazine (ADB) Feb 2005 fork seal article...

[mappsterr]

Excellent - thanks Kicken.

[crfsonly]

pretty slick idea (pun intended).

ken

[mprentice]

Just to follow-up on my original issue...turns out my hypothesis was correct. The damper o-rings were leaking pretty bad....in fact, upon disassembly, the left one was half full(not half empty). When I compressed the rod, oil would ooze out of the rod. So all that oil was emptying itself into the outer chamber.

Lucky for me, I met a guy at one of our local tracks who was a tech at a suspension shop not too long ago. He was able to rebuild them for me and make good as new!

[crfsonly]

great news. thanks for the follow up info!