I changed out my alternator about a week ago and momentarily disconnected my lower rad hose where it goes into the T-stat housing to do so. Don't ask why, it didn't help. I burped the system until I saw no bubbles, topped up, and thought nothing of it. Since then, I've noticed my coolant reservoir has been bone dry, even after driving, and my upper rad hose has been swelling a lot and far hotter than I ever recall. I figured there must be more air in the system or my T-stat is stuck (new OEM T-stat last year), but I performed another burping session today and only had a negligible amount of bubbles come up. I ran the truck this morning for 40 minutes (parked) with the heat on full and turned the interior into a sauna, so it is blowing hot air. I don't have a scangauge or IR gun so I was not able to get engine or coolant temps, but my temp needle never wavered from halfway. Lower rad hose never got past "kinda warm" to the touch, likely from ambient temps, upper rad hose could have melted my skin off. I ran the truck with the rad cap off, no funnel at first to observe if coolant was flowing into the reservoir when it reached the small hole, and it was, so a faulty rad cap could maybe explain why my coolant reservoir is empty, and maybe even the swelling hose due to not releasing pressure, but what about the T-stat? The coolant was damn near boiling when I finally shut the truck off and I really don't think the T-stat ever opened as the coolant just kept rising in the funnel.