Years ago, I had purchased a Bullet Proof FF7 bumper with the sole idea of using it as my air tank. The Bullet Proof bumper was advertised as being air tight and ready for being used for this purpose. So now was the time to see if it lived up to the advertised expectations. Needed for this part of the project are a 7/16" drill bit, 1/4" NPT tap, 2 - 1/4" NPT male quick connects, a drain valve, assorted wrenches and of course Teflon tape.
1. The bumper was removed and 3 holes were drilled on the passenger side with a 7/16" drill bit. Two holes on the very back and one on the bottom to be used for a drain valve.
The drain valve hole was strategically drilled to allow me to drill all the way through to the upper hoop so that the hoop also contributed to the overall tanks air capacity and would also be somewhat protected by the dangling clevis. See Figure 1.
2. Each hole is then carefully threaded with the 1/4" tap.
After all the holes were drilled and threaded, a small mechanics telescoping magnet (small enough to fit in the holes) was utilized to remove all the metal shavings from inside the bumper.
3. The drain valve was installed on the bottom hole and the 2 - 1/4" NPT male quick connects were installed on the 2 remaining holes on the back of the bumper utilizing the Teflon tape.
The bumper was then pressurized and checked for leaks by inserting it into a bathtub full of water. (Believe me when I say... this is best accomplished when the wife isn't home.) Well, after all the experience I had putting the air manifold and oil removal filter together, the quick connects and drain valve were leak free. Unfortunately though, there were two leaks (not just one) in the bumper. One at each end... so much for the advertising. Fortunately, my highly trained welding skills would only require me to grind, spot weld and check for leaks no less than 4 times before the leaks were finally eliminated. Each welded area was painstakingly prepped and repainted for that like new look. Bumper completed. See Figure 2.
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