Bulldozers winch spill

Rope winch oil leakage phenomenon at a GJT112 bulldozer appeared in construction. Pull the rope was found after all, the hydraulic oil is leaking from the winch at the seat bolts, and when stepped on the gas leak quickly, almost no oil leakage at idle.Preliminary analysis may be caused by loose bolts or gasket is damaged, but after replacing the gasket and tighten the bolt test machine, the fault persists. Further analysis of the hydraulic schematic view, 80Hp small swamp dozer may be due to poor oil return, resulting in greater backpressure. So the return pipe winch to manipulate the valve replaced, and that the inside of the tank by welding the parts back to the oil on a short tube, put the machine back to the original than some thick hose pipe, so that the end is not connected to the return line control valve, and directly connected to the new oil return spool, to reduce the oil return back pressure. Again the test machine, Chinese Earthmover the fault disappears