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CP4 to CP-ISB21S3 (revised CP3) change for 2021 6.7L Diesel Trucks -- Merged Threads

Wayne007 said:
That's very possible but I distinctly said CP4 pump. My thoughts are what else do we do? Trade it for what???? Every one of the big 3 has something that's not right. How long before the '21's start showing some defects? I'd get rid of it now but my '69 GTO won't pull a trailer ;):D
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389 or 421 motor? LOL
 
PLEASE stick to the technical, TSB, and/or recall aspects of this issue.

To those that have mostly adhered to the spirit of the thread, thank you all.

To those that continue to crap in this thread with significantly off topic discussion and rants that belong elsewhere, please stop.

It's good that the thread is garnering a lot of attention but it's starting to get mocked for being such a sh*tshow. The sheer amount of OT posts and BS don't do us any good.
 
Here's my fuel pump in my 2021 3500. No idea if it's cp3 or what
 

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GBB said:
It’s a CP-ISB21
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Yes, and it sure makes me feel more comfortable seeing that bolted to my '21 than the CP4.2 did bolted to my '20.

That being said, I wish there was a little more detailed info on the actual differences technically between the CP3 and the new pump, which is clearly based on the CP3 design.
 
Wmhjr said:
Yes, and it sure makes me feel more comfortable seeing that bolted to my '21 than the CP4.2 did bolted to my '20.

That being said, I wish there was a little more detailed info on the actual differences technically between the CP3 and the new pump, which is clearly based on the CP3 design.
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We will wait and see but dollars to doughnuts there is no real difference and the only reason it got a model name change is to avoid any potential litigation. There will likely be some minor change so they can have a backup if it ever gets to that point. Think about the people that have already swapped in a CP3 or further more have had to spend thousands out of pocket on rental/towing costs. This is just them covering themselves against any legal liability.
 
It's likely geared different to boost the pressure needed that the CP4 put out. Basically, what they should have done in the first place, what they proved was easy to do, and proves once and for all that the aluminum cheaper to build CP4 decision was 100% based on cost reduction and not mechanical inability of the old design to meet new performance standards.
 
Somewhere there might be an ID tag on it. Under it, or facing the block or some PITA spot. If it's a 21, it's a good pump. No worries.
 
There is a tag on it.

hdrams.com

CP4 to CP-ISB21S3 (revised CP3) change for 2021 6.7L Diesel Trucks -- Merged Threads

Not surprising that some units of poor design survive by pure random dumb luck. Some 6.0 Fords ran a while. When I was in the OPE business Kohler came out with the KT17, which was a notorious grenade, but they didn't all come apart. Lots of other examples exist. I think Ram may be the only...
hdrams.com hdrams.com
 
That sounds like a generic repair proceedure for a blown CP4. I can't imagine they want to keep repairing thousands of units rather then just replace with updated pumps to eliminate what I guess is a COSTLY warranty repair.. I guess we will know in a month...Tic Toc.....
 
exiledinaz said:
That sounds like a generic repair proceedure for a blown CP4. I can't imagine they want to keep repairing thousands of units rather then just replace with updated pumps to eliminate what I guess is a COSTLY warranty repair.. I guess we will know in a month...Tic Toc.....
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Not just a generic repair, but leaving owners hanging with a pump that can let you down at a bad time or spot
 
I'm hoping for a recall, noticed what looked like metal flakes the last time I changed the fuel filters.
 
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