Looking for some help guys. I have a 2002 JD 270 that starts up fine but will only stay running if I disengage the parking brake quickly. If I leave the parking break on, as soon as the hydraulics pressurize, the joysticks move forward automatically and kill the engine. I've replaced the key switch and parking brake switch and the parking brake solenoid checks out good. With the parking braked disengaged, everything works great. Any ideas? Thanks