[Bulldog]

Can someone tell me where the vacuum breaker is located in a 2011 3400RL. It's not under the bathroom sink and I can't find a trap door in the wall of the pantry which is behind the shower wall. I really don't want to start cutting holes looking for it, if I can help it. Appreciate any help.

I tried using the black tank cleaning sprayer and there was water leaking under the trailer and I couldn't hear it spraying on the walls of the black tank.