job just purchased a old A187 s40xl hyster forklift at auction for a few hundred bucks. I was sent out to test it out and inspect it before he bid on it. everything seemed to work fine there at the auction yard, however once it got delivered to our shop now it is stuck in reverse. so far I have tried swapping the solenoids to see if one is faulty. no change. I have swapped the forward and reverse valves. no change. ive replaced the o rings on the valves. no change.replaced trans filter.no change. ive even ran it with the solenoids removed and still stuck in reverse.
if I press the forward button on the pedal it will make it stop reversing as long as I'm holding the button down.

I'm assuming this means there's an issue in the reverse drum/clutches causing them to have pressure applied ? I'm not ver versed on equipment as I was originally hired to maintain the companies fleet of vehicles but I find myself working more and more on lifts and hydraulics lately and been pretty much just figuring it out as I go.

any help or a point in the right direction would be greatly appreciated.