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Message: <blockquote data-quote="zghorner" data-source="post: 3220303" data-attributes="member: 35089">Ford and GM went to the bosch CP4 from the CP3 in 2011+ while Ram kept the CP3. They basically come apart by chewing themselves up internally and contaminate the entire fuel system with metal. so all injectors, lines, HPP, rail and everything has to be replaced. Here is some info about a lawsuit filed against ford about it: <a href="https://www.carcomplaints.com/news/2018/ford-67-cp4-fuel-pump-failures-lawsuit.shtml" target="_blank">https://www.carcomplaints.com/news/2018/ford-67-cp4-fuel-pump-failures-lawsuit.shtml</a>This info is stolen from another forum:"Cummins used the CP3 starting years ago and to current. The Duramax also used this pump up through the LMM engines, or ending in 2010. The CP3 is a very good pump and has the advantage of being able to deliver *a lot* of fuel volume thanks to three fuel pistons. In 2011, Ford and GM both moved to the next-gen Bosch pump known as the CP4 which is a higher pressure but lower volume twin-piston pump. Cummins continued with the CP3 (which like the CP4 has seen revisions along the way).The CP4 pump fails when it doesn't get lubrication, and all of the pump's lube is from the fuel. Ultra low sulfur fuel doesn't have a lot of lubricity in it anyway, so any small amount of fuel contamination can cause the failure. Water in the fuel would be probably the biggest cause. There is a lot of speculation on the Internet that the CP3 didn't have this problem because it flows more volume, and more fuel must equal more lube. I don't buy that theory because the CP3 is a triple pumper while the CP4 is a double pumper, so the actual area needing lube is less in the CP4. Others say the CP4 in the Duramax fails more often because they don't use a lift pump (through the LML engine ending in 2016) but I doubt that as well. The CP3 never used a lift pump either. Now, the Ford 6.7L used a modified CP4 starting in 2015 which employed a new coating on the pistons...designed to reduce friction and help the pump survive small amounts of water. There were more modifications to the CP4 on the Ford engine in 2017, but these were more likely to support the higher torque rating. Starting with the L5P Duramax in 2017, GM has moved away from Bosch and now uses Denso to supply the entire fuel system of the Duramax. Cummins continues with the CP3. This is very interesting, in my opinion. Cummins could choose to use the CP4, GM could have chosen to stick with the CP4, or Ford could have chosen to move away from the CP4. Yet none of them did those things. Ford did increase the water separator capacity for the 2017 Super Duty; but aside from that I think they are satisfied with the reliability of this fuel pump. And there are plenty of very high mileage early Ford 6.7L diesels with original pumps that are doing just fine. So as with any diesel, choose the best diesel you can - high volume fuel stations...and drain your water separator monthly if you can."</blockquote>

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