rear tractor tire tube problem

Got a puzzler on my 2030 diesel...rear tire was seeping calcium from valve. I always keep some valve core housings in stock, so no problem swapping one out (I thought)..Jacked tire up, moved valve to top, and removed core housing. Usually lose a little air swapping housings, then re-inflate and problem solved. This time, lost no air...didn't give it much thought so put in new housing then checked tire pressure...none !!! Pumped in a bunch if air, rechecked and still nothing..did it twice more ( I could hear air going into tire), still nothing!?!? By now,I knew something was not right as tire was hard as a rock and I had no idea what pressure might be. (Tried two different gauges, also tried them both on front tire to make sure gauge was not at fault) Then I removed new core housing and gently poked a small dowel into valve. Felt like I was pushing on the side on an inflated tube !?!? Something was acting like a check valve of sorts letting air in but not out.?.? Tire is hard as a rock with core housing removed.?.? No idea what pressure in tire is, and no way to let excess out...Anybody ever experience this? I never have in my 76 years...I need help. Thank you...Dan

get a samll drill bit 1/16 and drill it out . has to be a build up inside the tube. plus u need that air released!

The core housing has a Schrader valve in it. The core housing goes into the stem of the tube (or the rim for a tubeless tire). I don't understand how you poked a small dowel into the valve, unless you are poking at the Scrader valve inside the core housing. Pulling the valve core housing opens up a hole about 1/4 inch in diameter inside the stem of the tube, not a little hole to be blocked. If the hole in the stem is blocked by something I would be getting the tube changed, because it sounds like the tube is failing. JMHO

Update!! Wasn't sure what else to do (last time I had a tube installed cost was $350, and I getting too old to change it myself), I drove tractor up and down driveway a couple of times then checked pressure with gauge...Must have moved whatever the blockage was, it now read 55psi. I rapidly let out a bunch of air, and all seems well now...however I still find it puzzling...Dan