CP3 & CP4 pumps

[Hay Dude]

had an enlightening conversation with a diesel mechanic with over 30 years rebuilding engines and about the CP3 & CP4 pumps.
He has only replaced 2 CP4’s in 200-450HP tractors, including AGCOs and CNH brands and only one was a failed pump. The same failure rate as CP3 pumps.

I asked him why so few CP4 failures in tractors and so many CP4s in pickups.
He said most of the newer large AG tractors running CP4s have a very high GPM gear pump running behind them pushing fuel into them, whereas a pickup only has a low GPM small electric lift pump pushing fuel into them.

Hes convinced the low gpm fuel lift pumps cause the CP4’s to fail. Large AG tractors rarely have CP4 failures.

 

[LightningCamaroGuy]

Don't the PSD trucks have a lower CP4 failure rate than the old Duramax and Cummins trucks that used to run them?

 

[Hay Dude]

Don't the PSD trucks have a lower CP4 failure rate than the old Duramax and Cummins trucks that used to run them?

I would think they have the same failure rates, but Ram has a higher replacement rate since they volunteered to replace ALL CP4 pumps at no charge.
Ford only replaced them when they failed, which is BS if you ask me. I don’t know what GM’s policy is.

I have no idea why a CP4 pump would last any longer in one brand or another unless it was backed up by a stronger lift pump.

 

[ericm979]

This article kind of implies that the lack of lift pumps might be a cause of failure: https://www.motortrend.com/how-to/what-is-cp4-failure/

Also its interesting that there are replacement pumps and kits that keep the pump from circulating debris through the entire fuel system.

 

[Hersheyfarm]

I would think they have the same failure rates, but Ram has a higher replacement rate since they volunteered to replace ALL CP4 pumps at no charge.
Ford only replaced them when they failed, which is BS if you ask me. I don’t know what GM’s policy is.

I have no idea why a CP4 pump would last any longer in one brand or another unless it was backed up by a stronger lift pump.

Ram had a couple of fires and they jumped in before a recall could be issued. For whatever reason their setup had a fire potential. A difference in the different brands could be the filtering and supply like you said.

i’m on at ford-truck and the other diesel truck forums and see these failures from time to time. I‘m on my 10th or 11th diesel superduty and have had minimum major issues, 6 with the 6.7 and probably 500k with just those Trucks and very high idle time. Lately it seems like an uptick in the failures. Not sure how i feel, dont like the design of the cp4 but still havnt had an issue. My 2022 f350 is at 110k, I’ll probably get another truck later this year. Getting tired of minor issues with fords. Hate ram, migh look into gmc. Since 1997 I haven’t owned anything but ford diesels so lost at features/quality of gm products.

oooh, on edit i just remembered its time to change the filter. Think i got 2k more miles left.

 

[Hay Dude]

You wouldn’t “hate Ram” after you owned one.
I was a Fordie for life until they screwed us bad on the 6/6.4’s.
Never again.
Had a 2007 Duramax and never should have sold it.
Now I’m in a Ram and with the Cummins and after 4 years, its the best truck I’ve ever owned.

Ram proved to me they were serious about customer satisfaction by replacing the CP4s rather than allowing them to fail while pulling a trailer up or down a mountain.
Afterall, you only get a few pumps on the brakes once the pump takes a dump.

 

[Hersheyfarm]

Rams junk, Chryslers whole model was to be the harbor freight of the big 3 and now the Italian company said hold my beer. I had a dodge pickup that fell apart.

 

[Hersheyfarm]

You wouldn’t “hate Ram” after you owned one.
I was a Fordie for life until they screwed us bad on the 6/6.4’s.
Never again.
Had a 2007 Duramax and never should have sold it.
Now I’m in a Ram and with the Cummins and after 4 years, its the best truck I’ve ever owned.

Ram proved to me they were serious about customer satisfaction by replacing the CP4s rather than allowing them to fail while pulling a trailer up or down a mountain.
Afterall, you only get a few pumps on the brakes once the pump takes a dump.

Again, ram burnt a few trucks up with the cp4, they were under investigation from the NHTSA when they “voluntarily” did a “recall”.

 

[Hay Dude]

Ram replacing ALL CP4 failed or unfailed.
Ford waits till they fail, then replaces.

Which is a better outcome for the customer?


I know I’d rather take mine in and have it replaced before it fails. A failed pump could get someone killed. Guess Ford isn’t worried???


As far as your brand bashing comment on Ram being “junk“, I have weight tickets Ford wont dream of pulling.
Other than the CP-4 and a wheel bearing covered under warranty, I‘m completely satisfied. Been a great truck and I’d buy another

 

[Hersheyfarm]

they were gonna have to anyways, the goverment would have made them. Curious how f’n bad you have to make a vehicle that burns up when the pressure pump implodes? Wtf did they do. Gm and ford pumps grenade and no flames.

imagine the engineers that signed off on that fuel system design, what else did they sign off on. We already know ram cant make a front end that doesn't fall apart.

and yea, ford will do everything they can to deny the cp4 warranty. I have no idea about gm. Never owned one. But I've owned dodge….