Part Number 385311238 — replacement O-ring for the discharge and inlet fittings on the VG4 Vacuum Generator (also known as the JW-series). Prevents vacuum leaks at critical plumbing connection points. The Dometic VG4 is the widely used vacuum generator in modern marine VacuFlush sanitation systems. It operates at 6 amps (12V DC) or 3 amps (24V DC) and connects to the sanitation plumbing via 1.5-inch inlet and discharge fittings. These fittings are secured with O-ring seals that are constantly exposed to the pressure differential maintained throughout the vacuum system. Over time, these O-rings can harden and lose their elasticity, resulting in vacuum loss that causes the VG4 to cycle on frequently between flushes. If your VG4 is running more than it should, or you notice a gradual drop in vacuum pressure at the toilet, the fitting O-rings are an excellent and inexpensive first diagnostic step before replacing larger components. Fits: Dometic VG4 / JW12 / JW24 Vacuum Generators Seals both discharge and inlet plumbing fittings Prevents vacuum loss and reduces unnecessary pump cycling Genuine Dometic replacement part Sealand part number: 385311238 Installation tip: Before installing, clean the fitting seat of any residue from the old O-ring. Apply a small amount of silicone grease to the new O-ring to ensure a proper seated seal. Consider purchasing our Minor rebuild or Major rebuild kit for the best value.
