Review on Dometic 385230335 Traveler Lite Vacuum Breaker Kit with Spray: Efficient Solution for Hassle-Free Travel by Ron Long

Back of the toilet. The repair will take a few minutes, simply gently pull the existing block from the back of the dresser which is usually far enough from the wall to accomplish this by blindly reaching backwards and gently pulling/twisting until it pivots (fragile plastic tubing, so don't cut it), then flip sideways and reinsert the vacuum breaker, then blindly reach backwards and reinsert into the back of the dresser. You don't have to be a gymnast or try to disconnect the hoses while they're still in the back of the toilet. It's basically like a cork in a bottle, you just pull it out and put a new one in. VERY easy and less than 15 minutes. I recommend including a flush valve (water valve assembly) in the kit, just in case. Easier to hand and cheaper if you don't wait for an immediate fix.