Guys, I’ve got a JD120 s/n POO 120 032208 that is leaking hydraulic from under the center of the machine. I initially thought it was a leaking track drive line or fitting but after giving it a good power washing, the oil is actually coming from the swivel ring down inside the machine. I first thought this may be from the swing drive shaft seal leaking, but looking at the parts and service manuals, it appears the swing drive unit has its own oil supply separate from the hydraulic swing motor. Oil in the gearbox unit is normal. Now I’m thinking hydraulic swivel in the center of the machine, but if that had leaking seals, would the oil leak into the swing gear area, filling it with oil, then allow it to run out of the swing joint and down under the machine. I don’t really want to tear things apart that aren’t a problem. Thanks
Hydraulic oil will accumulate in the swing gear cavity if the hydraulic swivel (or rotary manifold ) seals are leaking. Remove the oval shaped inspection cover and gasket found on the main frame between the (2) boom cylinders The swing gear cavity should have about one or two inches of grease only. It should be quite obvious if there is any oil or water in the swing gear cavity. You mentioned the swing gear box oil is not going down so any oil found would be hydraulic oil.