The Infamous New Bosch CP4.2 Fuel Pump

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Goose55

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Hello. I am very new to the RAM forum and have worries about the new Bosch CP4.2 Fuel Pump that is being used on the new High Output Cummins 6.7, in the Ram 3500 Duelly, which I just purchased in January.

My Ram Cummins mechanic friend tells me that "9 times out of 10, it is air that destroys them." So, I have all kinds of concerns about this because I have heard that when the pump does fail, it is catastrophic, destroying the entire fuel system, including the injectors. Of course, I have a power train warranty, but is a "limited warranty," as are most in the auto industry.

What will happen if and when the pump fails? Will I be held responsible because Ram will claim I used bad diesel fuel, or did not properly prime the pump after bleeding off water from the fuel filters?
 
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Fuel35 67

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When ya change the filters, just turn the key to run, do not start! Do this about 5-7 times, this will prime the fuel filters and get any air out of them. Then you can start the engine.
 

Gr8bawana

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My Ram Cummins mechanic friend tells me that "9 times out of 10, it is air that destroys them." So, I have all kinds of concerns about this because I have heard that when the pump does fail, it is catastrophic, destroying the entire fuel system, including the injectors. Of course, I have a power train warranty, but is a "limited warranty," as are most in the auto industry.

Anybody know if this true or is just another internet myth being spread by someone who was told it happened to their girlfriend's dad's cousin's brother's uncle's grandpa's truck?
I seriously doubt it.
 

crash68

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^^^what he said about priming the system after fuel filter change.
Keep in mind that the CP4.2 is also used in the EcoDiesel, very few reported issues with these pumps. Just off the top of my head I can account for at least 2 million miles traveled that about a handful of EcoDs have accumulated.
Most of the bad rap the pump gets was from the original CP4 version used in the VWs and other vehicles.
 
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Goose55

Goose55

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^^^what he said about priming the system after fuel filter change.
Keep in mind that the CP4.2 is also used in the EcoDiesel, very few reported issues with these pumps. Just off the top of my head I can account for at least 2 million miles traveled that about a handful of EcoDs have accumulated.
Most of the bad rap the pump gets was from the original CP4 version used in the VWs and other vehicles.

This is very good to hear. I am greatly relieved. THANKS!
 

RandomRam

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^^^what he said about priming the system after fuel filter change.
Keep in mind that the CP4.2 is also used in the EcoDiesel, very few reported issues with these pumps. Just off the top of my head I can account for at least 2 million miles traveled that about a handful of EcoDs have accumulated.
Most of the bad rap the pump gets was from the original CP4 version used in the VWs and other vehicles.


Or GM that did not use a lift pump in the LML Duramax. The CP4 was doing all the work.
 

BossHogg

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Or GM that did not use a lift pump in the LML Duramax. The CP4 was doing all the work.

From what I've read over the years that was the issue with the Ford Powerstrokes also, no lift pump. My son has a 2007 Duramax but he installed a lit pump and hasn't had the problem. RAM uses a lift pump.
 

David Simmonds

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I have a 2019 Ram 2500 diesel. It is the version that has RAM letters on the grill not the usual ram logo on the grill. How do I know if I have the CP 4 fuel pump or the CP 3 fuel pump? Is the CP 4 only on the high output diesel?
 

Hardluck

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Well new to forum just had pump failure on my 2020 in shop 3 weeks no help to this point parts ordered no eta. Nightmare begins
 

Cummins3

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All new rams have the cp4.2 we r all. Screwed at some point or another
 

Fuel35 67

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There is a conversion kit to go to a CP3 pump.
 

Hardluck

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Yes we are. I have case manager and have been getting the normal BS Jargon with absolutely no action as of yet. They state we will authorize rental but not happened, Escalate parts not happened been getting emails advising parts are with no eta as of yet.
 

Hardluck

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Rental authorized is a pickup truck but not one you can use for towing! WTH does this do for me, my truck was purchased only for towing so there again no help from FCA as of yet.
 

JFV1134

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A few articles were posted last night that are claiming all 2021 Cummins Rams are now using a pump that looks very similar to the ole tried-and-true CP3. Fingers crossed as my 2021 3500 has reached KZ status!
 

FatCatOnSmack

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From my research it looks like adding a Fass fuel system can help a lot, as it delivers the purest, no water no bubbles deisel to the cp4. Looks like 700 us to buy the unit, and whatever installation costs. I'm going to call the dealer and see if they will do it so it doesn't void the warranty.
 

Slotcop

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My fuel pump just crapped out and took out the injectors is the report my dealer gave me today. 2020 Ram 2500 Cummins 4000 miles. Pump on back order. Is this the CP4 you are talking about?
 

Scottly

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A few articles were posted last night that are claiming all 2021 Cummins Rams are now using a pump that looks very similar to the ole tried-and-true CP3. Fingers crossed as my 2021 3500 has reached KZ status!
Got my 2021 and it does indeed have a CP3
 
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Goose55

Goose55

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Still waiting for a call from the dealership to replace this infamous Bosch CP4.2 fuel pump. It has now been over one year since I received the Recall Notice.
 

06 Dodge

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Still waiting for a call from the dealership to replace this infamous Bosch CP4.2 fuel pump. It has now been over one year since I received the Recall Notice.
I have been reading that dealers have been replacing them for about 3 weeks now, have you called & talked to your dealer lately?
 

fritotec

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got my fuel pump replaced under the recall. took them less that a week. last summer we didn't go more that 200mi. from the house with the toy hauler for fear that the pump would fail. I used lucas centane and stabil diesel to try and lube the pump but you never know. now that it's fixed I already booked a trip to North Carolina.
 

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