Alternatives to DCR Conversion for Notorious CP4 Pump Failure
- Power Forge Diesel
- Feb 24
- 3 min read
Everyone that has a CP4 pump (2011-2024 Powerstroke 6.7L, 2011-2016 Duramax 6.6L, 2019-2020 Cummins) needs to know that the current failure rate (Feb 2026) in the U.S.A. for the CP4 is every 1 in 14 trucks. That's 7% of every truck with a CP4. That might not sound like much, but in the diesel world, that is a ton. That is approximately 140,000 trucks in the US alone that have had a CP4 pump failure.
The Reality of Powerstroke CP4 Failures
Ok, so I'll mainly be addressing the Powerstroke guys, because your trucks are the majority of that 7% failure rate. So it makes sense right, if you own a Powerstroke with a CP4 you only have a 7% chance of it blowing up on you. So, you probably don’t have to spend thousands on a DCR conversion to avoid a cp4 pump failure.
That thinking would make sense, if that 7% wasn’t currently climbing. CP4 failures happen mainly because the diesel fuel in the U.S doesn’t provide enough lubrication to properly lubricate the pump. With a CP4 putting out pressures north of 30k psi, proper lubrication is a big deal. So the more miles all of these trucks put on year after year, and the longer the cp4 pumps operate without proper lubrication, the more failures will occur and that 7% failure rate will go higher, like it has been year after year.
Why Fuel Additives Aren’t Enough
Ok, well you might be thinking, an expensive DCR conversion can be avoided by just using fuel additives right? While I am a huge advocate for the use of fuel additives for proper lubricity for your entire fuel system and you SHOULD ALREADY be using it anyway, the CP4 pump has a design flaw that proper lubrication can't solve.
The “failure” of the CP4 pump isn't simply that it shuts off. The “failure” is sending fine metal throughout your entire fuel system, destroying everything in its path. That CP4 design flaw comes from the internal pump design specifically with its roller tappets. These tappets roll along the cam that is driven off of your engine. These roller tappets have no way of preventing them from turning. When they do turn the roller not cuts into the cam and sends fine metal throughout your engine.
Preventing Catastrophic Diesel Fuel System Damage
So now you understand that there simply isn't a cheap way to prevent the CP4 pump from destroying your entire fuel system. That 7% chance of it going is slowly climbing with each new failure while trucks climb in miles. Unless you want to be part of that growing percentage, you'll need to remove the CP4 pump to know for sure that you won't become a statistic and be left stranded. You'll want to install a disaster prevention kit while you save up for the CP4 replacement.
Comparing Pump Replacement Options: DCR, CP3, and CPX
What are your options to replace the CP4? Labor costs about the same for every option, so you're stuck paying that regardless unless you do it yourself. While the S&S Diesel DCR pump is the gold standard, it is also the most expensive. There is a CP3 conversion that is more affordable. But, the most affordable option is the CPX conversion Kit.
Let's dive into the RCD Performance CPX conversion kit. Disclaimer, this is still a CP4 pump, but it's highly modified to fix all of the problems the CP4 has. It pins the roller tappets, so it's impossible for the rollers to turn and produce catastrophic damage. Has new feed ports that help with flow and debris management, and is a direct swap with the stock unit not requiring any new lines.
Expert Diesel Repair in Yuma, Arizona
This is a great option for those on a tight budget. We at Power Forge Diesel in Yuma, Arizona always recommend the S&S Diesel DCR conversion over everything else since you're already going to pay us to remove the cp4 pump anyway.
We replace these often for our customers. We want to provide a solution that fits your budget. The need is already there. Taking a chance and gambling on a stock CP4 pump in your truck is an increasingly bad bet. Come visit us at Power Forge Diesel in Yuma, Arizona.
*Photos courtesy of Dieselworldmag.com
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