Black tank sprayer plugged

I have a check valve in the inlet, identical to the city water inlet. With this check valve, I am comfortable with tossing the vacuum break out. You see, the vacuum break will leak water by design, and it won't be in my trailer.

Well found mine under the bathroom sink as a member had already posted. Pulled it out and the spring loaded side was stuck..Also beginning to think the campground may not have had enough pressure. Putting it back together this evening before heading to Hocking hills in Southern Ohio for what they are saying it going to be a gorgeous weekend...