Using aft reserve tank?

[mjk1040]

It's possible PhilH. Diesel tanks should ideally be filled after every run while still warm. Hot extra fuel is returned to the tank, warming the fuel in the tank. Air space in the warm tanks allows for condensation build up which over time we know will pool at the bottom of the tank. Over time tank rusting can occur from the inside the tank.

[Viper]

Qr Bbpost...... Viper, have you heard anything about this?

Tanks will leak for a variety of reasons. What caused it in your particular case is hard to say without physically inspecting the tank and installation. Some things can be done to prevent a new tank from rusting out prematurely but for older vessels you're kind of at the mercy of the tank manufacturer's practices, the vessel manufacturer, the vessel's previous owner, and circumstances surrounding your particular boat's life.

It takes some rigging and can be time consuming depending on the application and access but it's not rocket science to pressure test a tank. Don't know that you have to "specialize" in tank testing, I don't specialize in it but I've done it numerous times. The only thing you need other than a few fittings is a pump to pressurize and a gauge to monitor. Those are things every marina with a shop should have already.

[Jeff D]

Phil H,
I had to replace the aft tank on my 1990 4507 model Californian in 2017 after it developed small fuel leaks. The carver provided tank was designed to rest in the bilge of the void under your aft stateroom bed. In my case, the HVAC drain for the aft had over flowed for a long time (probably before I bought YOLO... I am the fifth owner). The water contacted the tank contributing to the corrosion of the tank. But the damage was caused by three 'high points' that the tank rested upon. These fiber glass, high points created the actual holes that leaked the diesel fuel. A pressure test should provide you confidence that the tank is sound. Best of luck in finding a mechanic to conduct the test. Jeff