I have to pump down and change out a York h2cb036s06a. I found at the service valves are not the allen type I am used to seeing. they had deep caps on them and when I took one off, there was a pin underneath. It seemed to move with the cap as if the tightening of the cap depressed the pin to open the valve. Is this correct. If this is, then I assume that taking the cap off will allow the pin to come up, sealing the valve. I didnt look that good cuz I didnt expect to have to deal with this unit, but it turned into a full system upgrade.