I am new to ford explorers but not general maintenance on my vehicles. Today I flushed out the old transmission fluid by pumping it out thru the cooler line. It was black and thick. My question is related to the transmission fluid pump. Normally when I do this procedure, I disconnect the line to the radiator cooler and determine which way the fluid flows. This time the fluid seem to come out the top cooler line on the radiator and I began to flush out 2qts at a time. After 1qt I saw fluid come out of the radiator cooler as well, it should be the drain back to the transmission pan. So is the pump trashed? I cant figure out why the ATF fluid would flow in both directions. Unless the transmission pump is failing. And it was flowing slowly. Hopefully someone understands the inner workins of the transmission to give me some direction.