When the engine is off, is it ok to open the hydraulic line? I guess I want to know, is the line under pressure and would I loose my fluid. I want to check to see if I have a bad "O" ring at a union where I have a leak.:confuse:
What line are you talking about? If you shut off the engine and then move any hydraulic valves back and forth there shouldn't be any system pressure built up yet unless the line you are loosening up is connected to a hydraulic cylinder which has a load on it or a three point hitch cylinder and the arms are up. As to if you are going to loose fluid you are going to loose what is in the line and possibly more if the line is connected to and lower than the oil level in the reserviour.