A properly assembled fuel tank is essential for reliable, smooth operation of any glow or gas-powered RC airplane. DU-BRO fuel tanks are known for their durability and consistent performance, but like any precision part, they must be assembled correctly to prevent air leaks, fuel foaming, or feed issues. If you've never assembled a tank before—or simply need a refresher—this guide walks you step-by-step through DU-BRO’s recommended method for creating a clean, secure, leak-free installation.
DU-BRO offers a wide selection of fuel tanks in multiple sizes, making it easy to find the perfect match for your model.
Step 1: Disassemble the Stopper Assembly
Start by removing the center screw to separate the stopper, front plate, and back plate. This allows you to access the vent and feed line channels. Before you move on, make sure you’re working on a clean surface so no debris gets inside the tank.
Step 2: Prep the Vent Line
Bend the last 3/8" of the brass vent tube to a 30-degree angle. This ensures the vent line sits near the top of the tank once installed. A DU-BRO Tubing Bender (Part #785/786) is ideal, producing smooth, precise bends without collapsing the tube.
Next, cut a small piece (½"–¾") of flexible fuel tubing and notch one end. Slide this notched tubing onto the bent end of the vent line—this prevents blockage and keeps the vent positioned correctly inside the tank.
Step 3: Install the Vent and Feed Tubes
Insert the vent line’s brass tube into the rubber stopper. Then insert the brass feed tube—this is the tube that will connect to the clunk inside the tank and deliver fuel to the carburetor.
Attach flexible fuel tubing between the clunk and the feed tube. The tubing length should allow the clunk to move freely but not get stuck against any wall. DU-BRO fuel tubing is available in both standard and gasoline-safe versions.
Step 4: Build the Stopper Assembly
Remove the fuel tubing temporarily so you can slide on both the rear and front plastic plates. Insert the screw into the assembly and turn it just enough to engage the rear plate—but don’t tighten it fully yet.
Reconnect the fuel tubing to both brass tubes, then push the stopper assembly into the tank’s neck until fully seated. Tighten the screw carefully to expand the rear plate and lock the stopper in place. Do not over-tighten, as this can damage the stopper or deform the tank.
Perform a gentle pull test to confirm everything is secure.
Step 5: Final Checks and Installation
Hold the tank up to a bright light. The vent line should be near the tank’s top, while the clunk should rest near the back. Once verified, install the tank in your model:
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Vent line → muffler pressure fitting
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Feed line → carburetor
To complete your RC fuel system, DU-BRO offers high-quality fittings, filters, and accessories that pair perfectly with their fuel tanks.
A properly assembled DU-BRO fuel tank ensures consistent engine runs, easier tuning, and fewer in-flight surprises. Once you’ve followed these steps a few times, assembling a tank becomes second nature—giving you the confidence to build, fly, and enjoy your RC aircraft with maximum reliability.
To see all of our fuel tanks, click on this link.
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Assembling a Du-Bro fuel tank is not difficult, but you want to make sure that you get everything done correctly. Here is our suggested method for assembling a leak-free tank:
- Remove the center screw and disassemble the stopper assembly
- Input a 30-degree bend in the last 3/8" of the brass tube for the vent line. A Du-Bro Tubing Bender (part #785/786) works perfectly for this job.
- Cut a notch in the end of a short piece of flexible fuel tubing (1/2"-3/4" long).
- Connect the notched piece of flexible tubing to the bent section of the vent line.
- Insert the brass tube of the vent line into the rubber stopper.
- Insert the brass tube of the feed line into the rubber stopper.
- Use flexible fuel tubing to connect the clunk to the brass tube of the feed line. Size the fuel tubing so that the clunk is near the back of the tank, but does not get stuck in any position.
- Temporarily remove the flexible fuel tubing from the brass tubing on the vent and feed lines.
- Slide the rear plastic segment of the stopper assembly over the brass tubing on the vent and feed lines.
- Slide the front plastic segment of the stopper assembly over the brass tubing on the vent and feed lines.
- Insert the screw into the stopper assembly and turn it just enough to engage the rear plastic piece.
- Reconnect the flexible fuel tubing to the brass tubing of the vent and feed lines.
- Push the stopper assembly onto the neck of the fuel tank. Ensure that the stopper is fully seated.
- Carefully tighten the screw on the stopper assembly. Do not over-tighten.
- Perform a pull test on the stopper assembly to ensure that it is securely attached to the tank.
- Hold the tank up to a light. Verify that the end of the vent line is near the top of the tank. The clunk should be located at the rear of the tank.
- Install the fuel tank in your model. The vent line is usually connected to a fitting on the engine's muffler. The feed line is connected to the engine's carburetor.
