One thought... simple physics. Air rises, so give it somewhere to rise to. JMO.
I'm sure I've mentioned this before, but I use a home made vacuum system that uses compressed air. I use a glass Mason jar with bulkhead fittings and an SMC vacuum ejector (for 1/4" tubing iirc). For my suction line(s)...I have a single line for things like clutch bleeding, or I simply plug-in a tee so I can bleed both front calipers together or bleed both bleeder screws on a single rear caliper (many under-slung rear calipers have two bleeder screws).
I can bleed and refill a complete front braking system or clutch, etc in only a few minutes. One man job, no drama, no mess. However, even home made, it did cost me about $100 worth of parts/fittings/tubing, and you DO need compressed air to run it, but it does work very well.
I'll usually cut a piece of cardboard to fit snugly over a brake or clutch master cyl (if they're the cast aluminum ones, and not the round plastic bottles like on most sport-bikes). The cardboard is a splash guard. I can turn the vacuum on very slowly, and then just pour new brake fluid in the reservoir.
Now I understand that most people don't want to spend $100 bucks on stuff/parts for a powered vacuum system, but if you hate doing it as much as I did, it might be worth it...lol.
What I did was basically build a homegrown version of this:
http://www.amazon.ca/Mityvac-MV6835-Vacuum-Brake-Bleeding/dp/B0015POUXM
Rem
One thought... simple physics. Air rises, so give it somewhere to rise to. JMO.
I see that my comment about physics has been shot down with a response that is backed my far superior education than mine. However, I will say, that the MICRO bubbles that I seen rise in the small tubes that I attached to my bleeders did allow the fluid and air to pass. I agree with what Brian has written, but I can also say that when I did this process, I was finally able to get my brakes to work. Mityvacs are nice, but I didnt have any results using mine. Good luck with your aggravation!
I see that my comment about physics has been shot down with a response that is backed my far superior education than mine. However, I will say, that the MICRO bubbles that I seen rise in the small tubes that I attached to my bleeders did allow the fluid and air to pass. I agree with what Brian has written, but I can also say that when I did this process, I was finally able to get my brakes to work. Mityvacs are nice, but I didnt have any results using mine. Good luck with your aggravation!
He best chime in soon or this is going to get worse...
I'm not sure as he's been working on his wood....so he says.
Conrad, do we have clutch?
And thank you for the entertainment value that this has provided.
I just now realized that there is another method you might have tried. Using a syringe to push fluid up from the slave cylinder into the master. I have one of those devices that I purchased just in case I needed it but haven't yet.