Ohlins Forks 46mm Leaks Leaks and more Leaks
 

I have replace the fork seals in my sons 2004 DE300 once or twice a year and it only gets ridden 8 days a year. I have been using 46mm KYB fork seals and the tubes look pretty good with no significant wear, scratches or pits. I most recently replaced all of the bushings too. I seem to recall hearing the KYB seals are slightly 1mm shorter than the Ohlins seals but I have never seen the Ohlins seals as I got the bike with the red and black MSR or Moose seals in it.

We regularly depressurize the forks on the trailer and we use a cheap football between the wheel and fender to take some pressure off the forks while they are strapped down.

Is it possible the seals are leaking around the outside of the seal instead of past the fork tube sealing surface? I was thinking of trying a light coating of RTV on the outside of the seal next time in install them or maybe get some OE seals from Ohlins. I am sure they will only want my left ... elbow for a pair.

I have a set of Ohlins RXF48 forks on my 2014. I unsuccessfully tried to use a set of 48 KYB seals. They seemed to fit the shaft and the bore fine but the seal thickness prevented the retaining clip from engaging its slot ( slightly too thick ). I ended up with SKF fork seals and Dust Covers and they fit and worked perfectly. Maybe you can get a set of SKF seals for your Ohlins 46 forks.
Good luck!

Check fork bushings for play...

Thank you both, when I rebuilt them this spring I put in all new bushings so I will try a set of SKF seals next.

For it to leak around the outer edge of the seal you'd have to have some damage/pitting in the outer leg. Entirely possible though. Have a good look at the surfaces when you have them apart.

Check the play between the upper and lower leg. Should be a bit at full extension but not much by the time they are half compressed.

Make sure lowers are round, no damage, etc.

As I recall there were not scrapes or wear in the outer sealing surface, but I will look again and check with a bore gauge to make sure they are not oval. I have been using the KYB seals in my son's bike. I just checked my parts bin and found a set of 46mm Honda seals. I used a set of these Honda Seals in my Godson's GG 2003 SE300 forks and they seemed to work well. I will give these a shot since I already have them.

try cutting 5mm out of the seal spring or use a stronger spring had the same prob on a set of gold nitrate 46 s on a cr 500 had to shim the bushes and a stronger spring on the seal and that was with skf

That is a cool idea! I think I will try the Honda /non KYB seals first and if that does not do it I will use a tighter/smaller spring.

Well the Honda seals look to be the same parts as the Yamaha seals. The only thing that looked questionable was some very minor longitudinal scratches in the fork tubes. I polished them up and I will see how they last this time.