Does adding the disaster prevention kit and and Kennedy Twin Pump Deluxe kit lift pump prevent any catastrophic issues with the CP4 ? Is it best to just replace the CP4 with a CP3 conversion if it's possible ?

 

Are you talking about a LML Duramax or a 6.7?

The Kennedy lift pump referenced is a Dmax product:

https://kennedydiesel.com/product/ke...7-lly-lbz-lmm/

The 6.7 has always had a low pressure pump feeding the CP4, on the frame rails on the 2011-2016 and in the tank for 2017 to current. It actually is a very robust system.

The CP3 was never used by Ford on any application, Ford was HEUI until 2007, the 6.4 used a Siemens K16 based system and the 6.7 has been running the CP4 since day one. SPE has an aftermarket CP3 swap kit but the S&S stanadyne based DCR pump seems more popular. A DPK doesn't stop the pump from failing but a properly designed one contains the damage to the pump and immediate lines themselves not the rails, injectors and tank.

 

Ok, thanks for clarifying that. I thought the Kennedy pump was more of a universal lift pump kit. I was not familiar with the Ford setup...

Does a DPK give any warning signs to the driver that damage as occurred with the CP4 and it's contained and give enough time to take it to a diesel shop before it gets worse? I'm not familiar with how that works to prevent something catastrophic.

If I were to go with a used 2019+ Ford F350 or F450 and wanted to keep it for the long term and try for over 500,000+ miles on it, low maintenance, what would you recommend ?

Emissions deleted ?
SPE CP3 swap kit or S&S stanadyne DCR pump ?
DPK kit ?

I ask because, I'm looking for either a 350 or 450 to put a camper on the back bed to travel all across North America and I'm looking for long term reliability/durability with low annual maintenance costs.

 

Ford has by far and away did the best job with the low pressure fuel system of everyone that ran a CP4 so unless your chasing huge power no real need to touch it.

No, all a DPK does is bifurcate inbound fuel to separate low pressure lube fuel from high pressure fuel going to the injectors and then filters the return fuel from the lube fuel of the CP4. Thought being if the pump fails it fails at the cam and roller so that fuel is isolated. Doesn't prevent the pump from failing or provide warning. Best best to monitor performance is have an OBD2 dongle report on commanded vs. actual rail pressure, if there is a material delta between the two your pump is underperforming and probably on its way out.

If reliability is the top priority, a deleted truck with a DCR is probably your best bet. The DCR has been on the market for a while now with pretty solid results. SPEs CP3 kit is kicking around but not anywhere near as popular and some people don't like the fact it is a serpentine belt driven pump, that said all the dual high pressure pump fueler kits from the last 25 years have been belt driven pumps so I don't see the issue. RDC has the CPX which is a CP4 with pinned buckets and a built in DPK, I see it here and there but not often. To me not enough of an upgrade.

All that said, there are people that have put hundreds of thousands of miles on a CP4, there are 60+ million of them of various flavors in use worldwide. There is a famous series of youtube videos on a 922k mile old CP4 that looked great on tear down. But there are also pumps that crap out at 50k miles or less, even the 2020+ CP4s with the pinned buckets have failures.

 

After the pain of having one CP-4 failure I have been using Hot Shots Secret LX4 Lubricity Extreme and Everyday Treatment at the performance level at the same time. I have also been having the fuel filters replaced each time I have the engine oil changed. I admit to being paranoid. Wondering what some of the more knowledgable diesel people think about those pactices?

 

@Bigfoot 4x4 The level of risk acceptance that you have will dictate your decision. The CP4 can last a long time, but when it fails it does not give your much warning, sometimes none, ask @Ltngdrvr , his died with no warning in a rural area, so this is the highest risk. The next lowest risk is the DPK which will prevent a lot of damage and enable you to travel maybe 75-100 miles before the engine totally dies, S&S did a video on this with a purposefully damaged CP4. The best, from a risk point of view, is the DCR, it eliminates the risk and it is a very robust pump, it can even handle JP8. I am opting for the DCR in my 23 with 32K miles since I travel pulling a TT and I am headed to places where towns are not very close together and I am not very risk tolerant. I did not address the CP3 since it requires the loss of a second alternator and I think that it introduces more complexity to the fuel system and if you don't like risk I would avoid it.

 

So, either a DCR conversion or S&S DPK will prevent a major catastrophic event, the DCR is just more of a guarantee ?

If I choose the S&S DPK and the CP4 fails, will the S&S DPK save me thousands of dollars in $$$ and the repair will be much more minimal compared to stock ?

 

Very common practice for people to run a lubricity additive since ASTM D975 allows for wear scaring of 520um on our fuel while EN590 tops out at 460um. That said people who ran lubricity additives have still experienced pump failure, so not a silver bullet but a good idea. Personally, I would take the money your spending in fuel filters and add a DPK. Just my two cents.

^^^ pretty much nailed it.

In a nutshell yes, it is just how much of a bet do you want to make. Obviously a DCR takes the CP4 right out of the equation and based on the few years it has been out the feedback has been positive. Granted the sample size isn't the same as the population of the CP4 but the results are still good none the less.

A DPK saves the injectors and the low side fuel system but you could be offline for a period of time while the injection pump is getting replaced. Of course any mechanical failure could do that to you as well, I toasted my 48re in 2004 Dodge and spent two weeks in scenic Black Canyon City, AZ.... in August..... in the middle of Chrysler's bankruptcy....

A popular combination is DPK and if the CP4 craps out, replace it with a DCR but of course you have the risk of being stuck at the time. Everyone's calculus is different and of course there are tens of thousands of PSDs out there with owners who can spell CP4 much less know how to take care of it just tooling along. Kinda a crapshoot.

 

This is the video for the newer Alumina Duty trucks. They also did it for the older gen truck like I drive...



They purposely damaged the CP4 in each truck and ran it to prove it works. Go on YouTube and you can find these videos, watch yourself and make up your own mind.

I have one on my truck. Installed it in July 2023.

 

If you go over to the '17-'22 Super Duty forums..........cpobst just post last week that his CP4 failed on his '22 F-450 with 52k miles on it. Also, he lubricated his fuel from day one. Its almost like a crap shoot with these pumps, some get high mileage and some don't.

 

 

We will never know, But it would be interesting to see how various factors influence the failures
So what are the contributing factors. Why does one pump with additives die at 50,000 miles and others run no additives and get 500,000 miles?
Are some guys just lucky enough to run Exxon/Mobile fuel and not need the additives? Based on Speed Lake's latest additve test. It appears that Exxon fuel( and some others ) have no need for additives
Others buy fuel from companies that produce only the Federal minimum.How many of the failuires were Lessor qualitiy fuel?
How many failures are due to DEF, GAS or Water in the fuel?
Do trucks in high humidty zones get more water in the fuel and have a higher failure rate? Would draining the water seperator more frequently help?
What about fuel from areas that don't get winterized as much as cold northern state? If you gell up, there is no fuel to lubricate the CP4. There always seems to be lot of failures after a hard freeze in the south.
What about High Alcohol products like Diesel 911 that somebody uses after Gelling up. What damage does Alcohol cause? It has no lubrication and actually strips lubrication
The actual additive in a fuel additives is a very small percentage. The rest of the additive is a carrier fluid. When people double or triple dose their fuel. What effect does that excess carrier fluid have? Another issue that Speed Lake mentions in his additive test. Use at the reccomened dosage, Don't double or triple does, More is not neccessarily better.

The list goes on and on, as What could cause these failures. I'm not believing it's all Bosch's fault. Ford builds 28,000 to 32,000 Superduties a month for the past 17 years, Thats over 6 million trucks. And no idea what the split between diesel vs gas.is. But you are probably looking at 4 million plus diesel trucks with CP4 pumps having been built.

I know two people who have had CP4 fail. First person's pump failed at 110,000 miles and he had never changed his fuel filters. Didn't know he even had them. Treated the truck like the gas truck he owned before.
Second owner traveling cross country and pulled in a BP station and just grabbed the Green Handle like he did at home and filled the tank with Gas.

 

It was also a warranty repair. If he had a DPK installed the warranty would have been denied.

 

It is believed his truck had a RP7 pump and not the RP8 which is the latest and greatest supposedly. The RP8 version supposedly loosened up some of the dimensions to accommodate low lubricity fuel. Having said that, I don't recall seeing any CP4.2 failures from any 23+ trucks, but I could be wrong.

 

I would imagine the fuel at the pumps is the biggest variability, and unfortunately, it's the one thing we have 0 control over. We have to trust what comes out of the pump. Sure, we can try and choose stations that are cleaner/newer in hopes that their tanks and systems are in good shape, and/or we can choose a station with a high turn over, but that is all we can do, and we still don't know exactly what is coming out of the nozzle. Even when using "top tier" stations, we still just don't know, and there is no guarantee that what was in the stations tank the last time you filled up is the exact same thing that is now in the stations tank. Of course it "should" be, but how doe we actually know? Accidents happen, not only by us at the pump, but think about how many hands have had influence on the fuel before it even arrives at the station and gets pumped into the tank we fill from.

Thankfully, my truck does have the newest CP4 variant bering as it was built September 15, 2021, and I do have a DPK installed, and use a good fuel additive in each tank. I change my filters every 15k miles and I fill up from the same station when not on the road, and I save my receipts to prove I pumped "diesel" into the truck, but this is all I can really do. Heck, I even have locking diesel and DEF caps on my truck with different keys so I have to grab the right key to take off the right cap before I even fill up, but if what is in the stations tank is bad or wrong... none of that matters.

It really would be interesting to somehow see what actually caused each CP4 failure. I would still say that lack of lubrication and contamination would be the highest cause but that is only my guess.