Vacuum Breaker Replacement

Yes Mike, if you are talking about the black tank rinse system, leaking is a common issue. Mine is also behind the shower faucet, but many are under the bathroom sink. It seems not using enough water pressure, or too much, can cause them to leak. Most are of cheap design, and lots of folks simply remove/bypass them, although their purpose is backflow prevention. I rarely use mine, just dump a bucket of water down the stool after draining tank, and add another bucket after closing valve, to slosh while traveling, and keep tank bottom wet.

Jerry