odd....

i just got done done puttin my s-10 back together suspension wise, bed is still off...well i crank up and let the compressors run for quite some time like 15 minutes, i try lifting at about 5 minutes figuring surely that'll have enough pressure to lift up some and no, the valves click but barely any pressure goes in the bags like just enough to stiffen up the lower bellow. well i finally give up and kill the compressors so i decide to take out one of the plugs to see if there's any pressure or how much and not a single air purge....valves are hooked up right and plenty of teflon tape on everything...i'm running two 5 gallon tanks with a viair 380 on each and 8 1/2" parker valves...what has me confused is fact that no pressure building in either tank and i have em hooked up seperately. lookin for hints as to what could be happening to keep me from having air buildin up in the tanks...any help greatly appreciated