I have a tandem ranger trailer with disc brakes on the rear wheels. I replaced the complete surge brake actuator. It has fluid coming out of the master cylinder after i primed it, I put a suction bleeder on the farthest wheel until i had clean fluid coming out. The other wheel not so much it wouldn't pull the fluid to that side even if i pulled the main line going to the caliper this puzzles me it should be pulling fluid thru a main brake line. Also why is their 2 bleeders on each caliper? Any thoughts but it's getting dark so i will resume tomorrow

If I'm understanding you correctly, the only thing I can think of that would keep fluid from flowing through the hose is a clog somewhere.
If that is the case, you may have to take the line off and put some compressed air in to blow it out. Same for the bleeder.

the 2nd bleeder on the caliper is so that you can add another set of brakes on the other axle. If you did, all you would need is a short jumper from one caliper to the other and you would remove the bleeder and replace with the fitting you would need to connect the jumper line.