Back in the summer I was on this site with a problem of not being able to raise the wings of a 3615 Bushhog when hooked to th 2-105 White. Changed hoses, hose ends, cylinders,even using only one cylinder at a time. Nothing I did would allow the cylinder to raise the wing. I finally brought it to the shop one day and reached under the cab to work the levers on the position control panel while standing by the tractor so I could watch the hoses when the cylinders were activated. Determined that.when trying to raise or lower then the other hose would act like it was locking up, ie: no oil would flow through it. Thus determined that the check valves were not opening where coupled together from bush hog to the tractor. I changed the female ends at the tractor to match the ends on the cylinder hoses, and guess what......the wings raised and lowered as they should. Spent a lot of time and money trying to figure that one out.