B190 Enthusiasts

Okay, mine cracked over the weekend - I mean, it actually developed a small hole between the threads.

No amount of pipe thread could stop the leak. Moreover I discovered that because of that I wasn't able to pressurize the water system (even relatively low pressure with the pump), which meant that I didn't have water in the camper.

So, lesson learned - have a spare of that plug. I went to an RV dealer and got two for $4.00 or something. Also it occurred to me that if I had installed the water heater bypass (for winterizing), I could have simply bypassed the water heater and still had running water in the camper.

Skater,

Knowing this is quite an old thread. Are you referring to the white plug that is on the lower left side, under the access cover on the outside ? 15/16" white plug?
Oddly, mine started leaking this weekend. I winterized using air, and then filled with the pink stuff. The day after I winterized I noticed a small puddle below the area where the access panel is. Thought maybe it was excess from when I opened the drain briefly. Last night I noticed that the puddle was bigger. Opened up the panel and could see it was leaking from the bottom edge of the plug. I grabbed a socket and went to tighten it up. It was finger loose. I probably tightened it three turns making sure to not put very much pressure on it. The leak appeared to stop, subject to looking at it today.
I used the Bus several times this year and never drained the water heater after. it never leaked a drop. Is the pink A/F so much thinner than water that it will leak? Or did I provoke it by putting pressurized air through there. I set my compressor at around 70 PSI. I figured the regulator would keep it at 40 PSI or so.

I went and looked a bit ago. no leak at this point. Has probably been 16 hours. Pretty sure I am good.

Still curious as to why now...

I wouldn't rely on a pressure regulator that's meant to handle water pressure to work on air pressure. I have no idea how they work, so I wouldn't trust it.

I think the usual recommendation is to keep the air pressure at 40 or 50 psi, something like that. I've had mine as high as 80 psi by accident, but only for a moment.

My plastic plug has leaked just randomly - I think it has something to do with being under pressure and heat, then not, then under pressure again, and so on, so after a while the plastic just starts leaking.