[scottz]

Originally Posted by mtlakejim

As listed 2018 Montana High Country 381TH.

I know we have discussed this issue to some degree in the past but I am wanting to get into specifics here.

First on the winterizing port. Is there in fact a check valve immediately behind the port that you screw the hose into? If yes, how do you access the wall behind the port to get at it?

What does the winterizing schematic look like between the port and the pump? I have been assuming based on conversations here that it is port/check valve/winterizing valve then pump?

Second on the Black tank wash down. Basically the same questions. Is there a check valve behind the port?

What does the black tank wash down schematic look like between it's port and the black tank. Based on threads on this topic I have been assuming it is port/check valve/vacuume breaker/spray nozzle in tank. If that is the case where is the vac breaker located, how do you access it and is it reaallllyyyyyy necessary? Also what type of spray nozzle is in the tank?

I setup the 12 volt water pump to supply the black tank wash line. I have noticed that it doesn't seem to put much volume or pressure to the tank based on what I see coming out of the discharge lines. I'm not sure if that is because the check valve is restricting flow, or the pump just doesn't put out that much volume or pressure. I do admit that I didn't try to wash the tank with a hose hooked to city water first to compare . Thoughts?

Yes, there is a check valve on my winterizing port (see photo). It is the same as the city water connection check valve and built into the fitting.

I'm not sure if there is a "check valve" on the black tank flush; I have not looked. There is an "anti siphon" device; mine is in the cabinet under the bath room sink. I just replaced the cheap plastic one with a brass one (see photo). I don't write the codes, but those that do feel it is necessary.

I doubt that your fresh water pump would put out enough volume or pressure to adequately flush the black tank.

I have a rough draft of my plumbing; it's on my "to do" list to draw it up properly. Bob's looks right.