It ensures that the fuel pump two-stage valve opens and the complete fuel system is primed. There is an optional Shop Pro 95 model with a 50 p.s.i. regulator for use on other diesel engines.

Ram and Jeep used the CP4 pump on vehicles equipped with the 3.0-liter Cummins diesel from 2014 to 2023 with Ram also using it on the 6.7-liter Cummins in its pickup trucks from 2019 to 2020.

That involves getting all of the air out of the system before they can start to pump diesel again. From memory, there’s a manual priming pump in the engine bay (I think near the fuel filter) and the ...