You can completely disassemble the valve to see how it works , it's very simple . You cant hurt it & it's good to lube it up with some WD-40 anyway. It has a huge soloinoid in it like out of a starter. You need to lube it at least a couple times a year IMO so the solinoid dont stick. At least I did but we get upper 20* weather here in the winter that may contribute to the sticking. Cant help on the pressure gauge part mine was disabled when I got it (i think). I only used it as a manual popoff. I do know the 3 large allen head screws at the base of the valve are how you adjust the pressure for the automatic side. If it was pre set previously , I wouldnt move those till I ran the boat a few times. Just my .2