Yeah, the other night we pushed in the schraeder. no moisture came out. I didn' do the soapy water test, but I otherwise couldn't hear or feel any air leaking.
That's a good sign, there may be a slow leak in the system but it's not the end of the world for now.
With no water pressure the air pressure should be 5 psi lower than your lowest operating pressure.
I don't understand what you mean by your last sentence.
Your pump is controlled by a pressure switch, correct? When that pressure switch gets down to X-psi it turns on the pump. The pressure tank when empty and just sitting there should X-5psi on the bladder.
As an example, my pump at camp kicks on at 45psi, so my pressure tanks when empty have 40psi on the bladder. If that ever gets low I just pump it up with the bike pump.
My best amateur guess is that the pressure gauge is no longer accurate, and the pressure regulator has either failed or needs to be re-calibrated.
The system may just need to be re-calibrated with the nuts and springs of the pressure regulator. It sucks living so far away from where the hardware is sold. I'll have to make one trip to town just to get another pressure gauge, and then another trip another day if there is something else wrong.
Can you jury-rig a connection from the bicycle pump to the pressure gauge and give it a couple pumps? That'll tell you if the gauge is working. Likewise the same fitting to the pressure switch and you should be able to watch the little contacts in the switch click over when pressure is reached and click back when it's bled off.
Even if the gauge is inaccurate the pressure switch is the important one. Some WD40/spray cleaner and running the adjustment screw in and out a few times might loosen that all up and get it working again. Just remember to count your turns on the screw so you can get it back to the same setting again.
How can you tell for sure if the bladder is ruptured? That seemed to be what people originally thought, but then we used the bike pump and things were as good as new for a few months.
If your bladder is ruptured the easiest way to tell is to let the system pump up and poke the Schrader valve on the top. If it squirts at you there's water in the bladder.
Thing is that even if the bladder is ruptured a pressure tank will still work. As long as there's an air bubble in the top of the tank it's still doing its job. Many cheaper and older tanks were bladderless and even modern ships hydrophores (nautical term for pressure tank) don't have bladders in them.
99.999% of the time, if your pump is short cycling it's because there's no air bubble in the pressure tank and it's just compressing against the hard steel instead of the soft air bubble. That or the cut-in (turn the pump on) pressure and the cut-out (turn the pump off) pressures are too close together. For reference my system at camp turns on at 45psi and cuts off at about 60psi. If your switch is too far out of whack and going from 35psi to 38psi it's just constantly going to cycle.
If I were to drive the hour each way from my camp to the hardware store for anything it would be the pressure switch. Maybe grab a gauge while I'm already there. The tank can be mitigated with a bicycle pump.
