Bleeding Hydraulic Clutch

So I have left on my new years riding trip today and ran into 2 problems. The first was solved earlier today by Kelly from Motorsportz who overnight me a replacement steering damper. He really came through on this as I would have no handle bars without it. Thanks again Kelly! A+ service from Motosportz.

Anyway, the 2nd problem is that I think I have an air bubble in my clutch line. It was feeling funny, so I took master cap off, and there was hardly any fluid in there. I got mineral oil at the store and poured it in the line and began pumping, and pumping, and pumping. Nothing helped so I decided I needed to bleed it. I have bled brakes in a car before and thought this was the same procedure. I opened the slave cylinder while squeezing the lever, then closed it, let go of the lever. Tried pumping the lever, and it didn't get hard. I then tried repeating, but because I never got any pressure in the lever it didn't force any fluid out of the slave.

It's after midnight, and I'm still working on my bike while everyone else is getting some rest for the ride tomorrow.

Any tips on how to bleed my hydraulic clutch? I read some posts, and a syringe and hose seems the way to go, but I don't have any of that here. I guess I could try a local auto parts store tomorrow?

Any help is appreciated.

If I recall you use a syringe and hose and push the oil up from the slave cylinder bleeder and out the master cylinder. Not sure why. That's all I remember. Good luck!

Also, is it ok to use mineral oil that I bought from the drug store? here is what I bought Will this work, or should I pick up special mineral oil from a bike shop?

Thanks!

Are you sure the seal has not gone in the slave ? Mine went a while ago and it seems a common issue.

As for bleeding, I used the syringe method but I don't see why the 'standard' method (i.e. the brake method) won't work.

I was always told not to use mineral oil from a drug store - in a pinch, absolutely (you can use gas if you need to apparantly - seals will then need changing though) but as a long-term solution ? No.

ATF is better the drug store mineral oil, plus it will swell the seals a bit. You can get the right sryinge at any horse oreinted pet food/feed store. Puching it up to the master cylinder is really the only way to make it work, the "standard way" my never get the bubbles out. Light fork oil will work too.

How can I be sure the seal has not gone into the slave?

On mine it was pretty obvious - the area around the slave had fluid all around it - when it was muddy the mud was clearly damp and a different shade to the rest of the engine. That and the fact the fluid level in the master kept going down. There's not a ton of fluid in the system as you know but it was clear on my bike that it was leaking.

BTW if it is the seal, it's a 2 minute job to change the seal - I got some upgraded seals from George at Uptite ($10 as I recall) and it's been fine ever since.

Good luck.

You can get syringes at any drug store, I got a handful for free (infant medicine syringes). Worked great.

P.S. I use Mobil I synthetic ATF & have had zero issues with it. YMMV

What syringes are you using? I got some infant medicine syringes from CVS and the size is totally wrong.

I've tried the mightyvac, I've tried the gravity bleed, I've tried the syringe, I've tried everything and zero pressure at all in the stupid line!

I use one of those turkey basking types from the kitchen ... ~6" long collapsed

The mityvac should work but the biggr syringes will work with a hose attachment. [pet stores have them] Those bubbles are hard to get out & if you have a seal probem it is almost impossible. Look at your slave cylinder & decide if you need a piston or a seal or the whole cylinder. Good luck. How's it doing by the way, I noticed it's been about 10 day's. I've also had to rebuild the master cylinder while troubleshooting & eliminating clutch problems. It can really be a bummer!!!

I use a children's medicine syringe, and one of the cone fittings from the mighty vac. (you can use vacuum hose also) Suck the fluid out of the reservoir and dispose of it. Take new fluid and fill the syringe. Push the air out of the syringe. Place the hose over the fitting and barely crack the fitting open. Push the fluid up to the reservoir. One more thing... there needs to be free play in the lever or the air (or fluid) will not be able to return to the top. I have found that sometimes it helps to lean the bike over to work the last of the air out after you do all you can.

The clutch can be bled either way, with the syringe or like brakes. The lever just never firms up like brakes do, but the process is the same.