Dometic Bellows S/T Pump Kit

The Dometic Bellows S/T Pump Kit is an essential replacement assembly for marine sanitation systems aboard cruising vessels and live-aboard boats. This bellows assembly serves the S-Vacuum, VG4-Vacuum, and T-Discharge pump platforms—core components of Dometic's trusted marine head systems used on thousands of vessels worldwide. If your boat's toilet flush action has weakened or the bellows shows signs of wear, this kit restores reliable operation without replacing the entire pump assembly.

The bellows assembly operates as the mechanical pump mechanism, converting manual lever motion into suction and discharge cycles that move waste through your marine sanitation system. Its white engineered plastic construction is corrosion-resistant in salt and fresh water environments—a critical advantage over metal components in the harsh marine cabin atmosphere. The compact 3 x 3 x 6-inch profile fits within tight head compartments typical on cruisers and sailboats. Note that this kit does not include O-rings (sold separately under part number 385310151); verify your existing seals before installation to ensure a watertight rebuild.

Boaters performing routine head maintenance or responding to sluggish flush performance will find this bellows kit a cost-effective repair option that extends the life of their pump assembly. It is compatible across the S, VG4, and T pump families, making it a versatile spare to keep aboard during extended cruises or coastal passages where service facilities are distant. Installation requires basic mechanical skill and a working knowledge of your Dometic head system; consult your vessel's sanitation schematic or contact Dometic support if you're uncertain about pump configuration.