With these bloody brakes you really need to follow the Avid bleed procedure.
Trying to suck air out of the top of the master cylinder just results in emptying the master cylinder reservoir . After flushing the system completely by working fresh fluid back and forth using two syringes, you absolutely need to use the Avid method of:
- close off the top syringe;
- draw a vacuum on the caliper syringe to pull any air out the system;
- once that's done, pressurize the lower syringe with the lever pulled into the bars and let the fluid pressure from the lower syringe force the lever back out.