Topic: Fork Oil Leak, But Why?

[Popwood]

I've been away for two weeks and the '75 750k has been sitting in the garage. When I go out to take I ride, there's a little fork oil on the garage floor. Never shown any leakage prior and I put new seals in a little less than two years ago. The leak was coming from lower part of the boot, just above the seal. I lifted the boot up and more oil dripped out, probably less than half an ounce total. Why would this happen after just sitting for two weeks? Granted, hot as hell so maybe the some oil has leaked out over time but just stayed in the boot, then the heat allowed it to start to weep out? I guess I'm also wondering if it is the seal, why so soon after replacement? I've put maybe 5 to 5,000 miles on since then.

Should I continue riding and just keep an eye on it? Should I drain that fork and put fresh in to be sure there's adequate oil? Other thoughts??

[Jerry Rxman Griffin aka MuthaF'er]

Steve,

I hate to ask the obvious but is it leaking at the copper sealing drain washer? That doesn't sound right with that much coming from the top when the reservoir is the lower part of the leg and the bike is sitting. Pooling behind the boot? Mine doesn't use the boot so I'm not so familiar with that. As far as the seals go I can think of 3 possibilities - installed upside down, not seated well or after market with only 1 wiping edge vs Honda with 2 edges. Hoping the tubes are straight and not scored. Another thought - what fluid are you using? Many guys use ATF instead of fork oil or regular oil. I believe ATF may help the rubber swell a little. How about switching before you feel it necessary to replace seals?! That's too big a pain in the ass.

[Popwood]

Thanks, Jerry. No leak from drain screw, just at the top. I'm using Honda seals and Honda fork oil. When I installed new seals, there was a score on the one tube that I filled with JBWeld, lightly sanded smooth and polished. Pretty sure the new ones are installed correctly. Just weird that it would start while sitting for a couple weeks. Or, as I said, the high heat may have allowed what accumulated to weep out. Oh yeah, I bounced the forks vigorously and inspected while the boot was raised and saw no new oil. Hmmm.

[BobbyR]

Actually the JB may be your problem. The usual fix is Crazy Glue which can really be polished. Was the score so deep you could not polish it out with some increasingly fine sandpaper and ATF using a shoe shine motion? I actually went as far as finishing them off with chrome polish. You want them like a mirror and a shot of silicone spray once or twice a year keeps them slippery. 
My Honda dealer told me if you can feel it with your nail, it will cause a leak. My first seals failed in 2 years, after a real pain in the ass polish job, 4 years and nothing.

I would dry it and keep an eye on it. It would be hard for you to duplicate the sudden shocks you will find out on the road. If you can make t through the season, you can sort it out over the winter.

[Johnie]

Sounds like the JB might be the problem. As long as they are OEM and installed with the lettering up you should be OK. Never had a new OEM seal failure. Might want to start looking for a new upper leg. You don't want to be doing seals every other year. Good luck with it Steve.