Replacing a Boat Fuel Tank

What You'll Need
New fuel tank
New hoses
Screwdriver set
Standard socket set
Working gloves
Protective overalls

Replacing a boat fuel tank can be done in an afternoon. When the tank is installed correctly, it will perform effectively as gas storage and may even outlast the life of a boat. The following steps can be used when replacing an old tank.

Step 1 – Inspect Old Fuel Tank

Remove the adhesive and shims holding the old gas tank in position. Inspect it and look out for damages, rust or corrosion. Check the fuel delivery system which includes hoses. Obtain new hoses and a gas tank to replace the old ones.

Step 2 – Drain Fuel

Use vise grips to shut off fuel lines and hoses and drain fuel from the gas tank, dispose it correctly. Remove the vise grips and reconnect the hoses. Make sure they are tightly fixed before turning on the engine. This burns solidified residues and any fuel remaining in the tank. Be careful when heating up the gas. Give the tank time to cool down.

Make sure that hoses to the gas tank are disconnected and disconnect the fuel gauge sending unit as well.

Step 3 – Remove Old Gas Tank

Locate the safety brackets that hold the tanks to its mounting position and take them out. Use a screwdriver to remove screws. If there are bolts use a wrench to remove them. Place the screws or bolts aside safely as they will be used in installing the new tank. Lift the old tank out and dispose of it properly.

Step 4 – Prepare Mounting Point

The mounting surface can be upgraded to protect the gas tank better; this is beneficial especially for tanks that sit on bare plywood deck. In this case, build a new deck and thoroughly glass over high-quality plywood. The edges on the plywood should be sealed effectively to prevent water from seeping in. To prevent the deck from sagging, add frames, especially if the fuel tank is considerably large.

Step 5 – Install New Tank

Position the new fuel tank on its mounting point and replace the brackets. Only use screws that are in good condition to fasten the tank in position. If there are openings for bolts and nuts, fix and fasten them properly. Make sure that the new tank is secure before replacing other components.

Step 6 – Reconnect Hoses

Only reinstall hoses that are in good shape. Attach the fill, vent and fuel hoses properly and secure them. Reattach the fuel gauge sending unit. Check that the hoses are well connected at the engine too and make adjustments if needed.

Step 7 – Refill Fuel

Pour in fresh fuel in the tank; it should reach the recommended level. Turn on the engine and inspect the connections on the hoses at the gas tank and engine, insure there are no leaks. Make adjustments if needed.