BD Diesel Common Rail Fuel Plug (2007.5-2018 Ram 6.7 Cummins / 2004.5-2010 Duramax)A very common failure of the 6. 7L Common Rail Cummins and Duramax is that of the pressure relief valve. These relief valves are a simple spring that is designed to relieve pressure as it exceeds a predetermined pressure. Unfortunately, as pressure is continually applied to this spring, it fatigues and does not have the ability to maintain even stock pressures. Now, throw pressure boxes and other power adders into the mix that demand higher rail