CP4 Disaster Prevention Kit from S&S Diesel Motorsports
I just recently finished installing a CP4 Disaster Prevention Kit (DPK) from S&S Diesel Motorsports on the 6.7 L Ford Diesel. The CP4 is the Bosch high pressure fuel pump that supplies fuel to the injectors. These pumps are very sensitive to dirt and water in the fuel and went they fail they fill the entire fuel system with bits of metal. To repair the vehicle after a failure of the CP4 requires the replacement of the ENTIRE FUEL SYSTEM. Very expensive!
The DPK creates a bypass on the fuel system that allows any debris created when the CP4 grenades to be trapped by an addition fuel filter added to the fuel return line.
It seemed like a good investment. It is a $400 kit that protects from having to replace the entire fuel system which is probably $10K if you do it yourself, and $20K if the dealer does it. Seems like a no-brainer to me!
This truck has 193K miles on it, and sooner or later that CP4 is going to grenade. With the kit installed, I will have to replace the pump and the return fuel filter and I will be done. Not a small job, but smaller than replacing the entire fuel system.
Normally, the fuel comes from the tank via 2 fuel filters and is supplied to the crankcase area of the CP4 pump. The fuel lubricates the internals of the pump and then is passed to the cylinders which boost the pressure to something over 20,000 PSI. Excess pressure from the crankcase is returned to the fuel tank. If the pump fails, metal debris travels from the crankcase of the pump to the high pressure section and is then delivered to the injectors. Injectors have microscopic orifices that become clogged by the metal bits and in addition these bits of that also clog the injector supply lines and are returned to the fuel tank by the high pressure return from the pump.
The CP4 pump is driven off the camshaft and is located in the lifter valley under the intake manifold. The DPK bypasses fuel from the crankcase of the pump and instead supplies clean fuel directly from the fuel filter. Bypass fuel from the pump crankcase is returned to the tank after it goes through an additional fuel filter thereby eliminating contaminating the rest of the fuel system.
To get to the CP4 you have to take the entire intake manifold off the engine, and to get the manifold off requires the removal of the both of the turbo charger charge pipes, several coolant lines, the low pressure fuel filter. The intake manifold is a two piece design, the upper made out of plastic. The upper manifold has 15 bolts that hold it to the lower manifold, and four of those bolts on the rear are very hard to get to under the cowl. It requires a small 1/4 inch drive ratchet with very short wobble or U-joint sockets to get to those bolts. There is not room under the cowl for the ratchet, a separate U-joint, and a socket. I had to get a set of sockets from Harbor Freight since I didn’t own any. (Yep, I don’t have EVERY tool made but I am working on it!) I also purchased a 1/4 extended reach battery powered ratchet, that thing worked GREAT! Once you have the intake off it is relatively easy to remove the control valve from the pump, put the adapter on between the control valve and the pump body and bolt the valve back in. Run the supplied hoses back to the original fuel filter and the added new return fuel filter and then put the whole mess back together!
I was quoted $2100 by a local shop to install the S&S DPK. I spent $400 for the kit, $200 for tools, and $3.49 for band aids. So for about $603.49 and 10 hours of my time I saved myself $1496 or $149 per hour for my labor. Not bad! And having done it once, I can do it faster the next time, when the pump needs replacement!