Fork seal problem

[James England]

Hi all...

I have a problem with my xjr1300 and it's driving me mad! I need a new perspective please......

I recently had the fork sliders powder coated. They were correctly coated, on the outside only with nothing on any of the inner surfaces or seal housing etc. Since I had the the sliders off, I renewed the fork oil seals with Yamaha replacements. The fork stanchions have no damage, rust, pits or anything. I put sae10 fork oil to the correct amount in each leg.

The fork seals keep leaking! I removed them and used silicone on the outside of the seals, just in case there was some sort of damage on the sliders. They are well sealed in. But the fork oil keeps leaking out from the inner lip of the seals.

Any ideas anyone??????

[DGXSER]

I had this once replacing fork seals. Not knowing the exact makeup of the XJR forks, on the XS11 forks, on the bottom of the fork tube is the sleeve, it has a sharp edge that can tear the seal. Either put the tube in before installing the seal, or wrap that sleeve with thin plastic to protect the seal.

[James England]

Just wondering...do fork seals go into the sliders in a ceain way? ie is it possible to get them upside down???

[bikerphil]

The flat surface on the fork seal with the numbers stamped on it faces upward. Are the seals really leaking badly or is it just a small trace of oil. If it is just a very small amount, it may very well dissipate to nothing over time, there may be excess oil trapped in between the upper and lower seal lips.

[James England]

The flat surface on the fork seal with the numbers stamped on it faces upward. Are the seals really leaking badly or is it just a small trace of oil. If it is just a very small amount, it may very well dissipate to nothing over time, there may be excess oil trapped in between the upper and lower seal lips.

Thanks. No, it's quite a lot of oil. It ends up splurging through the dust seal too and dribbling down the back of the fork leg!

The XJR has removable bushes top and bottom (which the XS doesn't) and someone said if they are worn, or the Teflon worn off them, they allow the fork stanchion to waggle slightly, just enough to allow oil past the seal...... Could be that....

[TomB]

The XJR has removable bushes top and bottom (which the XS doesn't) and someone said if they are worn, or the Teflon worn off them, they allow the fork stanchion to waggle slightly, just enough to allow oil past the seal...... Could be that....

If its worn bushes causing oil leakage the original seals would have leaked the same.

[bikerphil]

James, did you have the seals in the right way and what did you drive them in with? Those type upper and lower bushings can be shimmed from behind with a piece of feeler gauge if there is any wobble. My FJ forks are similar to the type you have. Checking the wobble requires laying the lower leg on the work bench, lightly clamping it down with the upper stanchion hanging out over the edge, then lifting up and down and checking for slop. Any fork can be checked that way but the XS type can't be shimmed. I have a good writeup about it somewhere, can't find it at the moment.

[bikerphil]

Here is that article if anyone is interested....

http://vmaxoutlaw.com/tech/fork_stiction_tuning.htm

[James England]

Follow up. Problem solved

Ok folks, I'm going to be completely honest and ruin any slight reputation I may have for knowing what I'm doing....all done so that others will benefit from my totally stupid inattention....

Firstly, when having the fork sliders powder coated, I had to remove two Teflon lined bushes from the sliders...one at the bottom and one at the top. I then had to replace them and also renew the oil seals.

First mistake...I damaged the Teflon coating on the top two bushes by using a small screwdriver to tap them in. It must have slipped and caused this damage




This, I think, allowed oil to get past the bush and underneath the oil seals...which I had put in UPSIDE DOWN..... I'd assumed that a slight bevel on one side was to facilitate tapping the seal into the fork slider. Incorrect! I ended up phoning Yamaha UK and their technical department put me right. The bevel goes at the top, along with the tiny numbers on the seal. Here's the seal..



There are the two sealing lips but also a third one between them which would appear to be important.....

I reassembled everything, using new bushes top and bottom and new seals. Problem solved. One consolation is that the bottom bushes were badly worn anyway and needed to be replaced...look at this wear....

[Schming]

Remarkable wear for relatively young bushes.

The triple lipped seals are for air forks and you can get by with two lipped seals, which creates less stiction, if you delete the use of air, but for me I like the extra security of "Three's a Charm"

As for your Rep. "One bad apple don't spoil the whole bunch."

[James England]

[QUOTE=Schming;435758
As for your Rep. "One bad apple don't spoil the whole bunch." [/QUOTE]hopefully my work on the new project may show that the rest of the bunch is fine! I'll be on familiar ground and working on a machine I'm well experienced in..... That's the theory, at any rate!