I have a L 3600 tractor that I have had to repair and replace two hydraulic cylinders on the FEL and repaired 4 on the Bradco back hoe all with these still mounted to the tractor. I did loose some fluid while doing this that was replaced, then I took the back hoe attachment off the tractor and tried to hook a grader blade to the three point hitch but it would not lift the blade. I took the blade off and was using the FEL to work on the drive way, when I looked back the lift arms where lifting but very slowly. Does any body know why the lift arms will not work? The spin on hydraulic filter has just been replace just before doing this work on the tractor. Thanks Dave