Perhaps some USA versions of the hoists lower only under gravity
However there are 6 dump trucks on my farm from 1949-54 on Chevy and GMC, 1-2.5 tons
Every one of them will lower under power
If you hold it in down position you Will hear the engine struggle and all the fine gravel on the frame crunches tight as all the hoses try to straighten out
I’ve never held it in that position too long to find out what gives up
There is no high pressure bypass in the hydraulic system.
Pto off the box can lower under gravity but it won’t be nice and tight to the frame so you get box jump on the bumps which I hate
So I make sure it’s sucked down tight
-s
