CPP’s Universal Fuel Tank Return Fitting
Classic Performance Product’s (CPP) Universal Fuel Tank Return Fittings are the perfect solution for adding a bung into a tank, reservoir, or catch can where welding is not permitted. Designed to make adding a return line for an EFI install while using an original equipment fuel tank, these aluminum bungs are available threaded for either an NPT (National Pipe Thread) or ORB (O-Ring Boss) fitting. Installation is simple, clean, and most importantly, safe. CC
The Universal Fuel Tank Return Fitting is essentially a rivet nut insert disguised as a bung. By tightening the provided Grade 8 fastener, once installed the body of the bung begins to collapse, securing the bung in place and providing a leak-free installation.
The first step is to choose the installation point for the bung on the tank, taking care to ensure there will be no intereference once installed in the vehicle.
Next, a step drill is used to make a 1/2-inch hole in the tank.
To install the bung, the AN fitting needs to be removed and replaced with the provided Grade 8 fastener.
That assembly is then placed in the 1/2-inch hole.
A 1-inch wrench is used to securely hold the bung while the fastener is tightened with a 9/16-inch socket or wrench. While the fastener is torqued, it will become progressively tighter, until the walls of the bung mushroom over and tighten against the inside of the tank. Once the bung becomes to collapse, the effort will get slightly easier and then difficult again. At this point, the bung should be correctly installed in the tank.
Here’s the bung with the AN fitting and return line installed.
The fitting can be installed on either a horizontal or vertical surface and even a slightly curved panel thanks to the oversized gasket.
This cutaway panel illustrates proper installation of the Universal Fuel Tank Return Fitting and how it seals against the inside of the tank.