For as long as the sun has risen Ram heavy-duty diesel trucks have relied on the Bosch CP3 high-pressure fuel pump to send diesel into the heart of two legendary 6BT Cummins engines; the late 5.9L and 6.7L. It’s the longest-running pump in the famous line of heavy-duty trucks, having been fitted from 2003 to 2018. However, in 2019 Ram engineers made the decision to move to a newer design with the Bosch CP4.2 pump.

“Chrysler (FCA US, LLC) is recalling certain 2019–2020 Ram 2500, 3500 pickup trucks, and Ram 3500, 4500, and 5500 cab chassis vehicles equipped with Cummins 6.7L Turbo Diesel engines. The High Pressure Fuel Pump (HPFP) may fail, resulting in a sudden engine stall without warning.”

What happens when the pump fails? It’s simple, really. Fine metal shavings from the pump’s internals are sent down the fuel system into your fuel rail, lines, injectors, and overflow system. They can’t be easily rinsed out so a full replacement of that end of the fuel system is the only way to correct the problem once it’s happened. The truck’s rendered inoperable in the meantime.