I had issues with these a while ago, the reservoir bladder had a hole in, so was leaking fluid. Replaced that, at last and tried to bleed and not getting anywhere.
In short, I can't force the fluid up from the caliper to the lever reservoir. I can't use the lever to pump fluid from the reservoir either.
When I squeeze the lever fluid flows, when I release the lever fluid flows back. It's as if there was some sort of fault with the lever, but I've no idea what.
I'm bleeding as per the instructions that are on Pinkbike, so it's not as if I'm doing it 'wrong'.
Any ideas?
Oddly, after I gave up and put it all back together ready to go to the bike shop it appears to be fairly well bled. I obviously can't test it until it's on a steep bit of ground, but seems quite solid.
Not really sure how I got fluid into the hose as I couldn't pump the fluid through, but I guess I'll see how it goes.
Although I can't suggest a fix from the details you've given there, we have just published a guide on how to bleed Magura brakes. It might be of some help:
http://www.epicbleedsolutions.com/blog/how-to-bleed-magura-disc-brakes/
Probably a bit late for the OP, and I don't anything about Maguras, but... from the description it sounds like the lever is permanently "closed". When you pull the lever, the first thing that happens is that it seals off the lever reservoir from the hose. When you release it, it reconnects the reservoir and hose, allowing fluid to move from reservoir to host to account for pad wear, and allowing you to pump fluid through when bleeding.
If the levers have bite point adjusters, is it possible that they've been screwed in to the point that the reservoir doesn't open when the lever is released? No idea if that's possible with your brakes, but it would give these exact symptoms.
can you not leave it to bleed 'naturally' overnight?
I left it over night, as suggested, and I've come back to it and the brake seems to work OK now. So I'll ride it and see what happens. Odd.
Had this problem with a Marta last week. Turns out from speaking to Magura that if you overtighten the stopped in the res on the lever it can crush the groove in the diaphragm seal which allows backflow of fluid when bleeding. Not sure if it needs a new seal or just the groove poking to open it up, but sounds like you have the same problem.