Converting a classic car or truck to electronic fuel injection often requires adding a return line to the fuel system. While many modern EFI-ready tanks already include a return port, an original-equipment fuel tank may not have the fitting needed to route excess fuel back into the tank. CPP Universal Fuel Tank Return Fittings provide a clean solution without requiring a return bung to be welded into the tank. These compact aluminum fittings install using a mechanical rivet-style design, making them useful for original fuel tanks, reservoirs, catch cans, and other applications where welding may be difficult or inappropriate.
CPP EZ Return Fitting Options
CPP offers two versions of the Universal Fuel Tank Return Fitting:
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Part #45111: AN6 male fitting with a 1/4-inch NPT adapter
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Part #45113: AN6 male fitting with a 9/16-inch O-ring adapter
Both fittings are designed to create a secure return-line connection through a 1/2-inch opening in the tank. The appropriate version will depend on the fitting style and fuel-line configuration being used in your build.
How the CPP EZ Return Fitting Works
The CPP return fitting operates similarly to a rivet nut. During installation, a supplied Grade 8 fastener is threaded into the fitting. As the fastener is tightened, the body of the fitting begins to collapse and expand against the inside surface of the tank. This creates a mechanical connection that holds the fitting securely in place. An oversized gasket seals the fitting against the outside of the tank, helping create a clean, leak-resistant installation without welding.
Before Beginning the Installation
Working on any fuel tank requires careful preparation. The tank must be completely drained, removed from the vehicle when appropriate, and cleaned before drilling. Never assume that an empty tank is free of flammable vapors. Work should not begin until the tank has been properly cleaned, ventilated, and verified to be free of hazardous fuel vapor. Keep sparks, flames, cigarettes, heaters, and other ignition sources away from the work area. OSHA guidance similarly emphasizes removing fuel residue and gas-freeing a tank before performing work that could create heat, sparks, or ignition hazards. When there is any uncertainty about safely preparing the tank, have the installation completed by an experienced fuel-system professional.
