Does the heat make the mineral oil in the clutch expand quite a bit? We've had > 100 °F heat indices for the last few days. Yesterday, when I got on my bike over lunch (it had been sitting in the sun all morning), I noticed the master cylinder was leaking (ARG, AGAIN) around the reservoir cap. I took it home and opened the lid and it burped out a bunch of fluid under pressure. When I replaced the master cylinder a few weeks ago, I intentionally left the fluid level a bit lower than the manual calls for, because of the leaking issues I've had in the past. I hadn't had any problems until yesterday. I opened it up and took some fluid out. But, now I'm wondering if I'll have to add some back in when it cools down. Is this heat thing going to be a constant battle with a hydro clutch? I've never had one before.
My friend with his new 630 also had some seepage the other day in 100 temps and removed the cap at a gas station and removed some by dipping a paper towel into the reservoir. Seems fine now however I did not experience this issue but he has over 1000 miles and I"m still at 600. Could be the clutch friction plates wearing. Did you notice the small pressure vent in the top of the cap (inboard side)?
I have over 7000 miles on my bike, but I replaced the clutch master cylinder at 4200 miles. I didn't notice the pressure vent in the cap, but now that you mentioned it, that's right where the leak was. It's still hotter than Hades outside, but my bike is in the garage. I might have to dump a little more fluid back in there. I'd hate for the level to drop back down and have it start sucking air.
