CP4 Replacement

R.S.O'Donnell

Senior Member
Joined
Feb 22, 2020
Posts
888
Location
IE of SoCal
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no 3rd a/c heat pump

In case anyone is interested us 6.7 Ford owners finally have an option to the CP4.

Until now there has not been a pump that would physically fit the relatively small space where the CP4 sits.

S&S Diesel has come out with what appears to be a bulletproof pump. Already got mine. Just gotta find a good shop to get it installed.

https://youtu.be/HHC4hM-w-Hk?si=bETm8V-o_ZysICXo

https://youtu.be/VMoJSVzwlnE?si=2d4Z2fWWOJzRJhFA

It`s a problem of the diesel fuel and the tree huggers taking out the sulfur that used to lube the pump.
So I use this and roll the dice.
 

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The piston can also rotate in the bore which has nothing to do with lubrication.

If you don’t already have one I highly recommend their DPK. I’ve done two coast to coast crossings with mine with no issues whatsoever.

If you do lose a pump you’re only out the pump and the filter.

https://youtu.be/F-vZEH1yEs8?si=QBJbLVjgdTEIQfsH
 

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no 3rd a/c..... Mini split

I believe the piston problems start from the lack of effective lubrication. But what do I know You apparently are an expert on the subject.
 
I believe the piston problems start from the lack of effective lubrication. But what do I know You apparently are an expert on the subject.

Not an expert…. Just have done lots of research. Just passing the info on. What people do with that information is of no concern to me at all.
 
From the internet:

Today's Ultra-Low Sulfur Diesel (ULSD) does not contain the lubricity needed to fully protect our vehicles. The Bosch CP4 fuel pump has an unusually high failure rate in the U.S., upwards of 7%, when compared to 1% failure rate in Europe..
 
In case anyone is interested us 6.7 Ford owners finally have an option to the CP4.

Until now there has not been a pump that would physically fit the relatively small space where the CP4 sits.

S&S Diesel has come out with what appears to be a bulletproof pump. Already got mine. Just gotta find a good shop to get it installed.

https://youtu.be/HHC4hM-w-Hk?si=bETm8V-o_ZysICXo

https://youtu.be/VMoJSVzwlnE?si=2d4Z2fWWOJzRJhFA

The 2018 example truck in the video demonstration, is example of what not to do….the truck owner had spent a lot of money removing the OEM fuel filters which were constructed of non rusting components and put in spin on filters and removed the on board water sensor. In short, even though the CP4 may have a track record of failures in the LML DuraMax engines, 2019, 2020 Cummins and 2011-current 6.7 ford, removing factory engineered equipment can add to the problem. In the 2018 test truck, if it didn’t have the S&S pump, the original CP4 pump would have failed from the rust generated by the aftermarket filtration system. As bshgto suggested, lack of fuel lubricity from pump grade diesel fuel, is a major contributor to high pressure pumps and injector failures of all makes. My office accountant’s husband has an injector rebuilding business with a sophisticated test bench similar to the S&S video, and he is an adamant supporter of adding lubricity enhancers such as Opti-Lube products. His take was that regular use of lubricity enhancers, would likely ward off most failures. Our fleet of trucks all use Opti-Lube added to each tank of fuel. The S&S replacement pump must be a recent offering. Previously S&S marketed a CP4 bypass kit that sends all the pump’s output to an external filter prior to it entering the injection system. The cost is currently $400 and is an inexpensive way to protect against a pump failure. Because the bypass kit is within the realm of do-it-yourself, it appeals to me.
 
I think the most important thing to remember is that, like all mechanical things, all CP4's will eventually wear out if run long enough. When they do the collateral damage is catastrophic.

Here are pictures of the lifter and roller. It has no bearing and no pressure lubrication whatsoever. It's just bathed in diesel.
 

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I am in the "If its not broke, don't fix it" camp.

In most cases I am too. But a failed CP4 is in the $10,000 to $15,000 range. That’s just too steep for me to risk it.

We just did a cross country trip from Florida. Every little noise worried the crap out of me. We’re currently In Quartzite in a “holding pattern” until we can get into our spot in SoCal. When we get the rig parked for the year I’ll feel a lot better.
 
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If the figures posted are correct, 7% of Ford diesels will have a CP4 failure. I follow a couple of Ford forums and almost certainly all 7 of those owners will post complaints about their pump failure. Almost as certain, the other 93 owners will remain silent. Therefore 100% of the Fords talked about on these forums have pump problems. That is how the internet works and causes people to panic. I hope your new pump works out great and also hope the rest of us fall within the 93 percentile.

Merry Christmas to everyone.
 
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If the figures posted are correct, 7% of Ford diesels will have a CP4 failure. I follow a couple of Ford forums and almost certainly all 7 of those owners will post complaints about their pump failure. Almost as certain, the other 93 owners will remain silent. Therefore 100% of the Fords talked about on these forums have pump problems. That is how the internet works and causes people to panic. I hope your new pump works out great and also hope the rest of us fall within the 93 percentile.

Merry Christmas to everyone.

I do too. I've searched for negative reviews and as of yet I've found none. I'll be sure to post back when I get it installed. Likely sometime in January.

Merry Christmas to you too.
 
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I use a lubricity additive. Hopefully that puts me in Europe’s 1% category.
If past performance is any indication of future results, I most likely will spend more to keep Monty working than the truck in the long haul, but, you never know.
 
Another option you guys should be looking at with trucks with a CP4 is the inline CP4 filter kit from S&S Diesel. This filter will contain the contaminents when your CP4 explodes, and keep all that crap from going through your entire fuel system. Those repairs can cost an average between $7000-$20,000.00. The kit sells for around $400.00 and a reputable shop can install it for $600-$800. My buddy just had his 6.7 Ford done. Glad GM/Chevy did away with that POS pump.
 

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