All the similar dump bodies I've worked with had a 3 position arrangement on the bed lever- - - -raise/stop/lower. All the PTO does is run the pump. You should be able to engage the PTO drive with the bed lever in the center position without anything moving. Move the lever one way to raise, center it to stop at any position you choose, and push the lever the other direction to lower. It's worth a try that way.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
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