Clutch Hydraulic Fluid Leak Question

[dank]

I noticed a slight leak on the left side in the area of the kickstand. Pulled the cover and it is hydraulic fluid from the clutch line. The source appears to be at the fixture where the line connects to the mechanism. (That was the highest elevation wet area and had a couple visible drops hanging on it.) I cleaned everything up. I tightened that connector's bolt about 1/8 to 1/4 turn, which was all I could tighten it. Everything else was too snug to tighten at all. Warmed the bike up and pulled the clutch lever 200 times. No drip anywhere.

My question for the better mechanics: Is there any reason to think the system encounters higher pressure and will leak under riding consitions? I don't see why it would, but I often find BD and others know things about how these systems function that are way beyond my knowledge.

[macmac]

The system isn't under pressure unless you are squeezing the lever IN. The mechanism is called a slave cylinder, the line is correct. i haven't been inside this cover ever yet, and so am not familar with the exact type of fittings.

There could be a bee hive nut and a alloy crush washer, with or with out a flare on the line.

SOmetimes these can vibrate loose and leak a few drops over time. i think you fixed it, but you should check in the resevoir, and be sure the level is topped up enough. You might be able to ck that by standing the bike straight up and looking in the window.

Wash and dry the areas that had fluid on them very well, as it will eat paint!

[dank]

Thanks! Fluid level is still good. I'm going to let it sit a while before I close things up, just to see if I get any drips. Sure hope not! Don't see anything else I could try to fix it if it drips.

Ah well. 34 degrees and looks like rain/snow. Can't rie, so at least I get to work on the bike. I guess.

[Yellow Jacket]

The clutch hose is attached with a banjo bolt. There are crush washers on each side of the hose fitting (qty. 2). These washers are sort of like the ones on the oil drain plug. They usually need to be replaced after one use. If it continues to leak replace the washers and torque the banjo bolt down to 18 ft-lbs.

[dank]

Thanks! Tightened the banjo bolt. Helped, but still a small leak. Tightened the three bolts on the face of the clutch slave cylinder. No leak in 4 hours. I'm going to close it back up and consider it fixed for now.

Thanks for the help!!!!

[ringadingh]

Thats actually brake fluid in the clutch slave cylinder, you may need new washers above and below the banjo fitting.I just changed mine last week and I think it was long overdue. The fluid was pretty dirty. However after changing it and bleeding the system, it feels exactly the same as before. I guess thats good.

[macmac]

Thanks Bob... Would you know if the crush washers are an alloy or copper?
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I suspect the banjo bolt was a tad loose from the factory, and the washers wore from vibration. IF the leak should occur again and you have not changed the brake fluid Dot 3 or 4, and NOT dot 5, should be used. If it were me I would chose Castrol Girling in Dot 4.

Anyway if the fuild has been changed and is recent, then tie the clutch lever IN as hard as you can. Meaning right up to the grip, and not using a Spanish Windlass to get it tighter...

The open the slave bleeder, and allow draining to happen, and refill just the slave (bench bleed) then change the crush washers.

This will reduce air in the system. With this done take a 13 mm short wrench and tap the slave cly first, then work up the line towards the master, tapping easy as you work up the line.

REEL EASY work the lever in one time still tapping the rubber flex line, and REEL easy let the lever out, watch for the bubbles to return in the master resevoir... Wait 5 seconds and repeat with the lever and the tapping, and in abiout 5 tries the system should be back bled, and function as it always did.

The very last thing to do is flail that lever and create the air into a froth.

For years I have bleed out trucks, cars and a few bikes that have rusted bleeders away to be just not there at all anymore..

Last Fall I blew a steel line on my 4x4 truck to the lf ft caliper and there is no bleeder left what so ever on that calpier and it works just fine now... I installed a new line and back bled it from the master.

[dank]

I agree. The leak has been there for some time. It was very slow and it had to have taken a while for enough to leak out that it start to drip out of the cover. My bike is 2 years old and I'm at just over 40,000 miles now, so may have been from the factory and vibration just worked on it over time.

[Yellow Jacket]

Mac, I don't know what the crush washers are made of.

[macmac]

My best guess is alloy because that is cheaper than copper.. That's a guess. Thanks for the reply...