|Odds are the coils on your old valve were getting weak and causing the weaving you described. On the new valve (depending on the tractor it was on last), there are orifices on the inside of the valve block that probably need to be moved to work with your tractor. I know when installing the valves there were certain orifices that had to be in certain plugs on the valve to allow the correct hydraulic flow. |
Try putting the old valve on with the coils from your newly acquired valve and see if that cures the problem. What happens is the magnets in the coils get weak. It takes more electric current to open and close when this happens thus causing to much flow and then tries to correct itself back the other direction (weaving).
If that doesn't work, try and look up on Trimble's website to see what orifices you need in which ports on their install instructions for your specific tractor.