First you will need to locate the pressure port on the drivers side of the trans located above the shifter linkage. For base pressure do not disconnect the harness and just check it at idle. Then to check max pressure you can disconnect the harness and run the engine at a 1000rpm. This should be pretty close to what you will see at WOT. Depending on if the trans is a factory unit or has been modified will determine what these pressures will be.