I've been helping my neighbor install a joystick control on his 4430 for the front end loader. We are running the loader valve off of a power beyond block. We got it all hooked up and when you push the joystick into float the loader raises. I have determined the return pressure is too high for the valve to allow the loader to fall in the float position. The return pressure is between 400 and 500 psi depending on engine speed. Is there anyway to check for a restriction in the charge pressure circuit? Or have I done something wrong. Thanks in advance for the help.