The Stovebolt Site Forums The Shop Area Engine Shop dual master cylinder brake trouble!

That initial spurt of fluid when you 1st press the pedal is normal. The M/C piston returns past the inlet port to allow excess pressue to backflow into the resivior (or with your high lines backflow the fluid, possibly dragging air past your rear piston seals) and fresh fluid to enter the lines as needed.
When you 1st depress the pedal that is the fluid in front of the piston coming out of the bore before the piston passes & closes the inlet port. You do not want to adjust this out as it is an important part of the operation.

When bleeding, pump it up till it's soid, then crack the bleeder & then close the bleeder wehn the fluid flow almost stops. No real time limit there, just dont want to draw air back in is all.
Definately wanna adjust all the brake shoes out to the proper clearance or you'll never get a firm pedal. Also, if you have done it once, rechecking it after you have pumped the brakes up a couple times may be in order as the if offcentered a bit your shoes can shift a bit when they contact the drums, widening the clearance again.
Otherwise, if you're not getting any air outta your bleeders and they aren't built into the M/C, a pair of residual press. valves may make the difference you need.