I'm still fixin cobbled up **** on the genny shovel - now I can't get the rear GMA B caliper bleed cause the mounting angle is 90 deg off stock for this caliper model - the guy must have gotten it bled out so there has to be a way - I had to disassemble it to machine reliefs in the caliper to properly clear the mounting tabs - it was actually sideways smashed up against the ribs of the caliper shell - here is a pic or the caliper from the top looking down - also a pic of the bike now

 

not exactly sure what the problem is but...
could you bleed with it off the bike and a chunk of metal about the size of rotor inserted to hold the pads apart?
BTW - i have found the Speed Bleeder valves that JP Cycles sells work very well for this PITA job.

 

The problem is the air is collected up at the top of the pistons - I can't push the air out since the bleeder is lower than the air pocket - the air is essentially trapped above the bleeder - the trapped air is more of an issue on the outboard piston side where there is no way of displacing the air from the inlet which is also lower than normal position

 

Take a NEW oil can, fill it with brake fluid and backward bleed it (pump the fluid thru the bleeder screw)...you will be done in 5 minutes.

 

I can try a reverse bleed - the master is below the height of the caliper though - and somehow the fluid will need to displace the air above the inlet port - but I will try it - its the only brake on the bike so I gotta fix it

 

This... I've had to do this exact thing numerous times with rigged up brake systems, bit of a pain in the *** but it works