Concur with Kent -- Follow his guidance.
On my more modern work/job equipment, as soon as the bed is raised to the desired position, I engage the clutch, disengage the PTO and use the raise/lower lever the hold/lower the bed from there. As soon as I am finished with raising the bed, I take the hydraulic pump (PTO) out of the equation to eliminate the possibility of an over pressure that could damage something -- even though there is a bypass in the system.
Remember, though -- operating this Class 8 equipment is a second profession for me and I am far from being an expert, this is just how I have been taught to do it by whom I regard as "competent authority." Let's see what Ed and the real experts have to say.
