WD 3 Point

The first and easiest to check is the traction boost control knob labeld "A" on your battery box decal. This is on the large plate located near the bottom of the pump. The plate should be rotated against the spring (counterclockwise I think) and the knob screwed into the pump body detent (be sure to clean the dirt out of the detent). Many times this knob vibrates out of the detent (and maybe out of the plate completely) and if you don't have the traction boost linkages adjust properly (or they are missing completely) the pump will go into full lift and ignore the manual controls.

The second possibility is in the pump itself. The pump is positive control to lift (a cam pushes the control valves towards the front of the pump) but the pump relies on a small spring to push the control valve back against the cam when it is rotated to the drop position. If there is any grit in the control valve chambers the valves can stick in the lift position. Another possibility, although less likely, is that the oil return chambers that allow the oil in the rams to return back to the reservoir (also internal to the pump) are completely blocked.

Check knob "A" first and then get back with us for further details on removing and disassembling the pump.