How to clear pool filter pressure gauge that is stuck?
My experience with pressure gauges is that yours is broken and unrepairable. The odds of an obstruction causing your issue is a long shot at best. You may be able to replace it with off the shelf parts. If you can connect a "T" fitting to the mounting hole install a gauge on one side and maybe an automotive radiator petcock to the other side. This will give a pressure reading and a air bleed port.