[jsmith948]

Replaced the plastic vacuum breaker/check valve assembly with brass fittings.

The OEM assembly was a bit of a challenge. Instead of being up inside the bathroom vanity, it was behind the shower wall. All four pex lines go through the floor at the same point, but the vacuum breaker was placed between the vent stack and the outside wall. Took a little finesse (and some sailor vocabulary) to get the breaker and the pex lines on the near side of the vent stack. Luckily, there was enough slack in the lines to let me bring the breaker out of the wall cavity to work on.

Replaced the OEM unit with a Case-Acme vacuum breaker and then added a Camco brass check valve (both from Amazon for $26) on the outlet side. Connected the new unit with Shark-Bite fittings.

On our previous trailer, I had replaced the plastic breaker with a couple of fittings. This worked, but I was concerned about back flow into the campground system. This set-up simply replaces the OEM with brass while keeping the intended function of the OEM fitting intact.

BTW - the compression nuts on the vacuum breaker and the shower faucet were less than hand tight. Weren't leaking...yet.