This article will mainly interest RAM 6.6 owners but it does mention the CP4 bypass for Ford 6.7 owners at the end. It is about swapping the CP4 for a CP3 as a precautionary measure

Think you meant to say GM 6.6 owners???

Idiotic move by Cummins to use the CP4 in their 2019+ engines. The Duramax is the smart diesel to get now, even with the DEF tank hanging off the frame like an ugly buck tooth.

IdaD wrote:Idiotic move by Cummins to use the CP4 in their 2019+ engines. The Duramax is the smart diesel to get now, even with the DEF tank hanging off the frame like an ugly buck tooth.The Denso HP4 is not without it's issues either in the medium duty world. We have had some HP4 issues come through our Hino and Isuzu dealerships.

ShinerBock wrote:IdaD wrote:Idiotic move by Cummins to use the CP4 in their 2019+ engines. The Duramax is the smart diesel to get now, even with the DEF tank hanging off the frame like an ugly buck tooth.The Denso HP4 is not without it's issues either in the medium duty world. We have had some HP4 issues come through our Hino and Isuzu dealerships.The CP3 isn't without issues either, but it doesn't grenade the fuel system when it dies. How is the Denso in that regard?

IdaD wrote:ShinerBock wrote:IdaD wrote:Idiotic move by Cummins to use the CP4 in their 2019+ engines. The Duramax is the smart diesel to get now, even with the DEF tank hanging off the frame like an ugly buck tooth.The Denso HP4 is not without it's issues either in the medium duty world. We have had some HP4 issues come through our Hino and Isuzu dealerships.The CP3 isn't without issues either, but it doesn't grenade the fuel system when it dies. How is the Denso in that regard?All HPFP send out metal fragments with they fail from roller to cam contact. However, the issue with the first version of the CP4 was more prone to this type of failure due to its cam profile and the filter on the MPROP valve would delim from valve leaving no filtering between the pump and injectors when it fails. Both issues are supposedly fixed with later versions of the CP4. I am still skeptical although I have not seen these issues arise with the updated CP4.How the manufacturer routes the fuel lines also has an impact on whether or not metal particles will get to the rest of the fuel system. If you allow the same fuel that lubricates the pump go directly to the injectors without being filtered, then you will have these issues. If you block off this fuel sending it back to the tank only feeding the injectors with fuel that ran through the filters and lift pump, then the filters will catch any metal big enough to be an issue. As far as the HP4, we have had to replace fuel systems on Isuzu trucks, but have not had to on Hino trucks from what I have seen.

Ram CP3 swap | Good Sam Community

25 Replies

S_Davis
Explorer
Jun 15, 2019
One thing I have noticed is in my 2013 Chevy the DIC calls for a new fuel filter about every 7000 to 8000 miles and my 2009 usually will go 14000 to 16000 miles before it says change fuel filter.
blofgren
Explorer
Jun 15, 2019
Exactly. It isn’t a problem until it happens to you. I will not give up my truck with the trusty CP3 to play Russian roulette.
ib516
Explorer II
Jun 15, 2019
So, either Ford has inadequately designed filtration system, or an inadequately designed HPFP system, or both. I feel sorry for this guy. There's no reason for a part to fail at 23,000 miles and have no warranty on a very expensive truck/engine. GM dumped that system, and Ram just adopted it. For the sake of the new Cummins/Ram owners, I hope Ram/Cummins engineers did a better job of designing the rest of the fuel system than Ford did.

What a nightmare.
Perrysburg_Dodg
Explorer
Jun 15, 2019
????? the CP4.2 is just as bulletproof as the CP3. Now when the CP4 first came out yes they were junk, but they have since fixed that.

Don
Cummins12V98
Explorer III
Jun 15, 2019
I have owned ALL brands of trucks. Cummins has been very good to me as has RAM. 5 RAM trucks with well over 500,000 miles accumulated I have good reason for loyalty.
IdaD
Explorer
Jun 15, 2019
Cummins12V98 wrote:
Bigfoot affair wrote:
Cummins12V98 wrote:
I have not heard of a newer Ford/Bosch issue.

I realize you want this pump to be reliable because Cummins is now using it. You really have to give your head a shake, 2017 F250 CP4 BOOM!

I really don’t care as time will tell. It sure is not going to stop me from buying a 2020. If at that time there are failures and denials of warranty I won’t buy one.

There are failures on everything but I stand by what I said there don’t seem to be many issues or denials on the newer Fords.

This is my father in law with Fords - that degree of brand loyalty is just baffling to me. It just, makes no sense...

They all make turds.
Cummins12V98
Explorer III
Jun 15, 2019
Bigfoot affair wrote:
Cummins12V98 wrote:
I have not heard of a newer Ford/Bosch issue.

I realize you want this pump to be reliable because Cummins is now using it. You really have to give your head a shake, 2017 F250 CP4 BOOM!

I really don’t care as time will tell. It sure is not going to stop me from buying a 2020. If at that time there are failures and denials of warranty I won’t buy one.

There are failures on everything but I stand by what I said there don’t seem to be many issues or denials on the newer Fords.
Bigfoot_affair
Nomad II
Jun 14, 2019
Cummins12V98 wrote:
I have not heard of a newer Ford/Bosch issue.

I realize you want this pump to be reliable because Cummins is now using it. You really have to give your head a shake, 2017 F250 CP4 BOOM!
Flashman
Explorer II
Jun 14, 2019
Two issues with the CP4 pump. Bad design - may be fixed with new ones - and Ford not honoring their warranties. GM VW and BMW cared enough about their customers to cover the bad pumps. Ford - not so much.
Cummins12V98
Explorer III
Jun 14, 2019
I have not heard of a newer Ford/Bosch issue.

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Ram CP3 swap

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