I just got a used lockout valve for my 425 to make my 40 loader bucket more responsive. It did that, but the valve leaks around the stem of the 'T' handle when using the hydraulics. I tightened the nut that the stem goes through and it did not stop the leak which drips slowly. Does any one know if there is an o-ring in there and if it will come apart and be easy to reassemble? I don't want to try and remove the stem and ruin the valve.