As many 6.7L Powerstroke owners have become painfully aware, the high pressure fuel pump (also known as a CP4 pump) has a design weakness. When the CP4 pump fails, it will shed tiny particles of metal throughout the entire high pressure fuel system. The only cure in this case is to replace everything in the high pressure fuel system - CP4 pump, fuel injectors, injection lines, fuel rails, etc. We hear from our customers that the total cost of this repair with labor can be in the $9,000 range.
The CP4 disaster prevention kit cannot prevent the CP4 pump from failing. What it does do is prevent the contamination from the failure from entering the high pressure fuel system.
The CP4 pump is internally lubricated by diesel fuel from the tank. After lubricating the crankcase area of the CP4 pump, fuel enters the high pressure pumping chambers and exits under pressure to the fuel rails and fuel injectors. The weakness of the CP4 pump lies in the crankcase area where a set of roller lifters ride on a camshaft. When the failure event occurs the lubricating fuel becomes contaminated immediately. Our bypass kit mounts to the CP4 pump and changes the routing of the fuel flow so that lubricating fuel from the crankcase is directed back to the fuel tank to be filtered before going through the fuel system again. Thus all fuel entering the pumping elements of the CP4 pump and leaving for the injectors is always routed through both of the vehicle's fuel filters to eliminate any chance of contamination from a high pressure pump failure.
