Air lock I believe in secondary loop

Mufichman

I installed to ultra 299 boilers. Lead boiler with a shadow that heats an aqua plus heater. They had primary secondary piping installed with the original boiler. I was planning on closing the valves leading to the secondary loop and just build a header for the two new boilers on the close ts. Long story short the valves wouldn't close. I had to drain down the secondary loop to change the valves and pipe new boilers in. I finished the piping and my supply line gets hot down to the t on my header (forgot to mention I used the easy up manifolds by Weil McClain for all the near boiler piping) I cannot get the water to move into the secondary loop which is hung on the wall with unistrut. My headers/ close ts on the secondary loop are connected at the bottom of the loop at the lowest point. It slopes up and hits an air eliminator with an auto vent on the top and the supply water piped into the bottom. The pipe then turns vertical to the circulator. It then turns back horizontal and picks up all then zones. Then goes back down and completes the loop. I suspect the 2" copper 90s on two top corners of the loop are holding the air. Both corners are the high points. The pumps are supported by unistrut but it sags in the middle. Cut out one 90 and installed a 2"x1/2"x2" t with an auto vent on one side. Am I on the right track ? Should I cut out the other 90 and install another auto vent? I believe I am air locked and it is driving me nuts. Please help.