Review on 🔧 Dewhel IPR Valve Air Test Fitting Tool - Enhanced Performance for Ford 6.0L Powerstroke Diesel High Pressure Oil System by Gerson Lagerquist

I had the same problem as many of the reviewers before me, with the small end having an unknown thread size. However, after spending some time at the local hardware store and trying both SAE and Metric, I was still confused as nothing fitted properly. A 12mm coarse thread screw would fit, but wobbled a bit and the 1/2" was too tight. So I went to the brass fittings section and found that 1/4" pipe threads fit into multiple threads quite easily. Then it will really snug.. I just want to screw in an air hose fitting so I can screw it in tight and then use a quick coupler with a 3 foot hose and a 1/4" ball valve attached to another hose fitting so it attaches my air hose can be connected.. apply about 100psi to the crankcase and watch for leaks. Using an IPR hole takes care of both sides. I used a brass fitting that was 1/4" male and 3/8" female. It starts off easy but tightens up quickly.Note that you can apply tremendous pressure as the HPOP exerts up to 3000psi when running.If this works for you, run a 1/4-Z oll line to solve it.