Problem solved. With much persuasion, I was able to separate the elbow for the pickup from the tank. The elbow was clogged with gunk. It seems to be from ferrous metal. Used a drill to clean out the orifice, wire brushed the threads, and used pipe dope from Boeing. The pick up tubes were clear. Same problem on both tanks. Lack of proper maintenance on the tanks. Still not sure where the gunk came from seeing how the elbows are stainless. I will now drain and refill the tanks with an additional filtration attached to the hose whenever I fill these tanks.