Clutch grease leak

Helitronix

Joined
Oct 16, 2013
Messages
138
Location
Marlborough, MA, USA
Bike
2006 ST1300
It appears that a small amount of grease is oozing out from my clutch lever and dropping onto the left fairing pocket cover. I learned that this grease is caustic, and actually stained the cover. It's a dark gray / black looking grease, looks nothing like clutch fluid, and appears to be leaking out of the pivot bolt area. Though I'll have to get a good picture and study it to be sure. I cannot prove it is grease. But the clutch fluid level is perfect, and it looks like different fluid.

It has happened twice in the last two months. I wiped the grease the first time and filed away a mental note to take a look if I saw any further signs. Now two months later, it did it again. The only thing in common between the two incidents, was that the length of the ride was in the 3+ hour range. I normally make it out for 2 hours at a time. These two rides happen to be longer.

Has anyone experience with this grease leaking out? Any ideas why? And what to do about it, other than clean it up? As I said, the grease is caustic and attacked the plastic pocket cover. I'd like to fix it so it doesn't happen again.

Thanks for any ideas.

Joel
 
If a previous owner greased it with a moly paste it could run out and drip like that. I stained a pair of gloves just like that. I don't think moly paste is caustic but it's nasty to clean up and gets on everything.
 
I've had the ST since October 2013, and it hasn't done this until now. So I was thinking that some trouble might be brewing. This stuff stained the plastic and won't clean off. Perhaps that means it's not moly paste?

Joel
 
Nothing caustic in there, might be some lube leaking out.
Pull the clutch handle. Clean the handle pivot, push rod bushing and it's blind hole, and the push rod.
Probably a good idea to have a new rubber boot on hand. Mine was toast at 97k as was the pivot bushing.
If you have clutch handle free play, take a close look at the pivot bushing blind hole.

Hopefully you won't find anything coming from behind the snap ring that retains the hydraulic piston.

Go easy on the lube on the handle pivot, push rod pivot and it's blind hole when reinstalling.

Moly would make a stain on the PP pocket cover as would hydraulic fluid.
Pull the handle and see if you find evidence of hydraulic fluid blowing past the snap ring.
 
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I'd remove the pivot bolt and clean up whatever is in there, from the sound of it you could have some kind of moly grease in there (its black). I don't know why it would be 'leaking' unless you're leaking a bit of clutch fluid and its somehow mixing with the pivot grease before finally falling off the lever. Check for hydraulic leaks with the lever off. After cleaning it up you could lightly lube it with some generic grease, but don't overdo it.
 
There isn't any source for grease to come from your clutch lever pivot bolt, except for whatever grease may have been there at assembly. It is a simple task to fix, though you may get dirty.
 

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This isn't somewhere I'd use moly (not a high temp bearing), but use some naptha or lighter fluid to clean it up. Toothbrush might help clean out the grained surface. Follow that with some isopropyl alcohol, then soap and water.... none of those should hurt plastic. If you still see a "stain" you could try some Mother's Back to Black.... apply to the stain and let sit for 3-5 minutes and rub while it is still wet. Then apply to the whole surface and let sit for a couple or three minutes, and wipe off.
 
Thanks to all for the feedback. And Soontobeone, that diagram and instructions was really helpful. I haven't removed the clutch lever before, so that diagram is great. I'll remove the parts, clean it up, and see if there is anything strange going on. I'll report back as soon as I get to examine it.

Joel
 
I took the clutch lever off last night and cleaned it up. The grease appeared only to be on the pivot bolt, and the sliding surfaces of the clutch handle, plus the acorn nut. The rubber boot was clean, and does not appear to be leaking any fluid.

I cleaned it up, lubricated it and reassembled. I'll keep an eye on it to see if anything strange develops. It's just strange that the grease dripped out after all this time. I don't know when the grease was put on, but I've had it for almost two years with no sign of this until now. Since there is always a root cause behind mechanical problems/issues, I'm not confident that the issue is resolved. But time will tell. If heat from the bike can cause that grease to liquify and drop out, well, then I might have my root cause. Two lengthy trips in hot weather precipitated this, but I just don't know for certain.

Joel
 
Helitronix said:
The grease appeared only to be on the pivot bolt, and the sliding surfaces of the clutch handle, plus the acorn nut.
Click to expand...

sounds a little over lubed to me. the pivot bolt is the only pressure/wear point, the sliding surface of the clutch handle shouldn't need to be lubricated, but I guess a very light film wouldn't hurt.
 
If the dark gray color wasn't grunge it could have been moly paste. Heat can cause the oil in the grease to come out of suspension a little.
It shouldn't cause any issues with the handle pivot but the push rod/pivot and rubber boot should be lubed with silicone grease better for the type of rubber used around brake fluid.
 
I now know have more data on this. It turns out that the clutch fluid was expanding and weeping out of the top of the clutch master cylinder. While working in the bike last weekend, I had the plastics off and the engine idling. A lot of heat is thrown off the bike when the plastics are off, enough to keep me warm in my garage with the door open and 32 degree temps outside! As the bike warmed up and up, I saw drops of fluid around the seam of the cylinder. And then I saw clean fluid leaking down the clutch handle and onto the acorn nut below. Once it touched the acorn nut, it was dirty gray. It must have mixed with the silicone lube I put on the bolt nearby. This was the caustic slurry that damaged the left front plastic locking cover that sits below it.

I imagine that a leak at this spot means that the fluid has expanded due to water intake over time. I'll check my records to see when I last changed the fluid. I changed it once so far since getting the ST in October of 2013. I'm wondering if I could have overfilled it. I never considered that overfilling was an issue. Now I know why overfilling would be a bad idea. I'll have to pop the cover and check the level to see if it is higher than it should be. I am betting it is. So I'll flush the system now anyway and get new fluid to the proper level in there.

Joel
 
I just noticed the same problem. Dark grey lube from underside of the clutch handle. I'll do the cleaning recommended in previous thread. Thanks,
 
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