I rebuilt the door hinges on my '51 3600. 3 were original to my truck and one was a used hinge I purchased from a forum member. He threw in a pair of new springs he didn't need. Rebuilding went as expected with the usual struggle to remove the old pins. Now with new oversized pins, no play in the hinges. However the hinge with the new springs flops about 15 degrees from the closed position toward open position. Hold the door member and the cab member just flops that 15 degrees. Springs look as if they'd fall out on their own, but they don't. Can't see that I've done anything wrong but something's not right. Suggestions before I take it back apart?