waste tank flush problem

[Navy Flier]

In my 03 Horizon there is a waste tank flush connection that allows me to attach a garden hose and spray water into the black water tank during and after dumping. All has gone well until the last time I went to use it. When I connected it and turned on the water I heard no water spraying in the tank as I have before. Upon disconnecting it was apparent that there was no water movement. When I disassembled the facing plate to get to the water lines I found that the lines go from the attachment point forward and up into the coach and them return to the tank. Upon contacting the Winnebago tech advisors I find that there is a vacuum breaker in the line between the attachment point and the tank. He said that the breaker was probably at fault. When I removed the access plate in the toilet area to get to the breaker I am faced with a mass of wiring and plumbing and cannot get to, or even see, any vacuum breaker. As yet I have not been under the coach to see if I can access the breaker from there. This may be one of those items that "never" fails and is very difficult to access. Any experiences with this problem out there?

[Navy Flier]

In my 03 Horizon there is a waste tank flush connection that allows me to attach a garden hose and spray water into the black water tank during and after dumping. All has gone well until the last time I went to use it. When I connected it and turned on the water I heard no water spraying in the tank as I have before. Upon disconnecting it was apparent that there was no water movement. When I disassembled the facing plate to get to the water lines I found that the lines go from the attachment point forward and up into the coach and them return to the tank. Upon contacting the Winnebago tech advisors I find that there is a vacuum breaker in the line between the attachment point and the tank. He said that the breaker was probably at fault. When I removed the access plate in the toilet area to get to the breaker I am faced with a mass of wiring and plumbing and cannot get to, or even see, any vacuum breaker. As yet I have not been under the coach to see if I can access the breaker from there. This may be one of those items that "never" fails and is very difficult to access. Any experiences with this problem out there?

[AFChap]

Hmmmm... maybe I had a problem with it once, but mine was a problem with flow in the wrong place rather than no flow... I connected the flush hose and turned it on. I could hear water more than I normally could. Then water started pouring out from above the compartment ceiling next to the water compartment and the wife started yelling from inside as I turned it off. Looking behind the galley cabinet between the crack in the counter top at the rear of the slide I saw wet floor. When I tried again, everything worked as normal and we've never had a repeat of the problem.

[Charles99]

My vacuum breaker and check valve "was" under the sink in the bathroom. My breaker also flooded the cabinet in the rv once, due to low water pressure. The breaker did not seal off. I have since removed the breaker, but left the check valve. No more problems.