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

MtnRider said:
Do you believe the fuel contaminants are some how getting "around" the filtration? It's being filtered down to 3 microns (at least 4th gens are) so that's pretty small (human hair is ~70 microns).


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Its not so much about clean diesel but pure diesel. Water containments play a huge part also. With this pump design, assuming 26k rail pressure and pump plunger diameter of 0.25" diameter the roller can see ~ 5,000 lbs of force spread over an extremely small area. Is it exceeding its tensile strength? Guessing so since we are seeing a higher than normal failure rate. If the roller assembly does rotate in its bore as the video suggests it can do then it will def fail. Remember its diesel fluid and not oil which has better lubricating properties that help reduce friction, heat build up, etc.

EDIT: In addition, if you run the new pump without 100% full of diesel it has a much higher rate of failure as it requires diesel for lubrication. Are people making sure they prime the fuel system after a filter change before starting the motor? I remember when I changed my filter on my CP3 trucks I just cranked it until it started which you could get away with on the old CP3 pump. I don't believe that is the case with the new pump.
 
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NDanecker said:
Its not so much about clean diesel but pure diesel. Water containments play a huge part also. With this pump design, assuming 26k rail pressure and pump plunger diameter of 0.25" diameter the roller can see ~ 5,000 lbs of force spread over an extremely small area. Is it exceeding its tensile strength? Guessing so since we are seeing a higher than normal failure rate. If the roller assembly does rotate in its bore as the video suggests it can do then it will def fail. Remember its diesel fluid and not oil which has better lubricating properties that help reduce friction, heat build up, etc.

EDIT: In addition, if you run the new pump without 100% full of diesel it has a much higher rate of failure as it requires diesel for lubrication. Are people making sure they prime the fuel system after a filter change before starting the motor? I remember when I changed my filter on my CP3 trucks I just cranked it until it started which you could get away with on the old CP3 pump. I don't believe that is the case with the new pump.
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Now that is interesting! I hadn't thought about filter change and priming being part of the failure at all. That said it doesn't explain all failures since there are many that have failed long before their first change.
 
3 microns if l am not mistaken would take 8465 particles stacked up to equal 1 inch..... thats pretty damn good filtration, l am guessing the CP-4’s failure is not due to contamination
 
leeroy300 said:
3 microns if l am not mistaken would take 8465 particles stacked up to equal 1 inch..... thats pretty damn good filtration, l am guessing the CP-4’s failure is not due to contamination
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and has it not struck anyone that the repeat ram owners had CP-3’s that never failed and l am quite sure they are using the same fuel source!
 
Lifter spinning in the bore is likely the most common failure as illustrated by the change to the symmetrical cam in the dimple pumps. The theory is they did that do lessen the aggressiveness of the ramp rate of the cam so it doesn't kick the lifter sideways as much. There likely is either a different gear ratio used in the dimple compared to the non-dimple or a longer duration time built into a wider flatter cam lobe to make up for the loss of lift generated by the asymmetrical lifter ramping. Either that or the dimples would make less rail pressure than the asym pumps.

This is why you see lubricity being the main thing people stress with these pumps. Water or contaminates = a scenario for that lifter roller to friction grab the cam and kick it sideways. If it's nice and greasy/slippery, the roller will have a much easier time staying put.

Also note that this is why higher end valvetrain lifters on engine like a GM LS use link bars. The aggressive lifts used in aftermarket cams would contribute to lifter spin. The link bars keep them tied together to prevent this.
 
NDanecker said:
In addition, if you run the new pump without 100% full of diesel it has a much higher rate of failure as it requires diesel for lubrication. Are people making sure they prime the fuel system after a filter change before starting the motor? I remember when I changed my filter on my CP3 trucks I just cranked it until it started which you could get away with on the old CP3 pump. I don't believe that is the case with the new pump.
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I know it has it in the diesel supplement for our trucks, and I'm pretty sure it's been in any older ones too, that you follow the priming procedure after doing fuel filter maintenance.
 
roflcopter said:
I know it has it in the diesel supplement for our trucks, and I'm pretty sure it's been in any older ones too, that you follow the priming procedure after doing fuel filter maintenance.
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I prime in my 2007. Key on and of at least 3 times until I no longer hear the lift pump running for a spell.
 
Brewbud said:
I prime in my 2007. Key on and of at least 3 times until I no longer hear the lift pump running for a spell.
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A mechanic friend works at a UPS shop and told me they recommend to fill the filters with auto transmission fluid when installing the new ones. Little priming needed, and extra lube for a few minutes after the change.

B
 
kobra said:
A mechanic friend works at a UPS shop and told me they recommend to fill the filters with auto transmission fluid when installing the new ones. Little priming needed, and extra lube for a few minutes after the change.

B
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I retired from UPS as a mechanic. We were told a long time ago to not use ATF on the newer emissions equipment. It is bad for the DPF. Or at least in the Ohio Valley district that was the rule. Now the old days it was common practice by some mechanics to use ATF. Not to argue but I would stick with recommended additives on newer emissions diesels.
 
Ah interesting; he's in AZ, they must be more old school at his shop ;)
So, when you do a filter change, do you put the filter back empty? Or fill with diesel fuel?
Thanks,

B
 
kobra said:
Ah interesting; he's in AZ, they must be more old school at his shop ;)
So, when you do a filter change, do you put the filter back empty? Or fill with diesel fuel?
Thanks,

B
Click to expand...
Well, fill with fuel if you can. But with the Ram you need to cycle the ignition a few times and the filters will be filled with fluid. Seems like best practice right now as we wait for a more permanent factory fix. Here is my list of recommendations I have pieced together from all the info out there. 1) Buy fuel from a good source. 2) Keep your fuel above 1/4 tank (to prevent sloshing fuel from aeration they say) 3) I add the recommended fuel additive. 4) Use the FCA filters when you do the change. The may be Fleetguards anyway. I think Jeno's garage had a decent price on them. In the owner manual they have the recommended bleeding by cycling 3 times. Also,
as soon as the water indicator comes on get the filter drained and as soon as you get the filter changed. I got some little 4 ounce bottles on Amazon and put 4 ounces of Diesel Kleen that Cummins recommends. I run down to a little below half a tank and add one of the 4 ounce bottles at fill up. I also got a plumber pipe plug that works great as a fuel cap to keep dirt out of the capless fuel port.
 
mra400ex said:
Well, fill with fuel if you can. But with the Ram you need to cycle the ignition a few times and the filters will be filled with fluid. Seems like best practice right now as we wait for a more permanent factory fix. Here is my list of recommendations I have pieced together from all the info out there. 1) Buy fuel from a good source. 2) Keep your fuel above 1/4 tank (to prevent sloshing fuel from aeration they say) 3) I add the recommended fuel additive. 4) Use the FCA filters when you do the change. The may be Fleetguards anyway. I think Jeno's garage had a decent price on them. In the owner manual they have the recommended bleeding by cycling 3 times. Also,
as soon as the water indicator comes on get the filter drained and as soon as you get the filter changed. I got some little 4 ounce bottles on Amazon and put 4 ounces of Diesel Kleen that Cummins recommends. I run down to a little below half a tank and add one of the 4 ounce bottles at fill up. I also got a plumber pipe plug that works great as a fuel cap to keep dirt out of the capless fuel port.
Click to expand...

Geno's has a filter maintenance kit with both fuel, oil, and air filter, all Mopar. $140.

Add a 28mm socket to your order if you don't already have one.

Mopar Quick Service Filter Kit for 2019-2024 Ram 6.7L

Get genuine Mopar OEM filters for your 19-24 Ram 2500/3500/4500/5500 6.7L Cummins. This Quick Service Kit includes air, oil, and both fuel filters for one complete filter change.
www.genosgarage.com

1611280508293.png
 
Brutal_HO said:
Geno's has a filter maintenance kit with both fuel, oil, and air filter, all Mopar. $140.

Add a 28mm socket to your order if you don't already have one.

Mopar Quick Service Filter Kit for 2019-2024 Ram 6.7L

Get genuine Mopar OEM filters for your 19-24 Ram 2500/3500/4500/5500 6.7L Cummins. This Quick Service Kit includes air, oil, and both fuel filters for one complete filter change.
www.genosgarage.com

View attachment 10924
Click to expand...
Too bad that Turbo Encabulator is on backorder. Was hoping to add it to my 2008 2500 to extend its lifetime a few more years.
 
MtnRider said:
Do you believe the fuel contaminants are some how getting "around" the filtration? It's being filtered down to 3 microns (at least 4th gens are) so that's pretty small (human hair is ~70 microns).


.
Click to expand...
I think the filtration system is fine. The CP4 is a horrid design with the internals able to turn directions and the roller run sideways on the cam lobe. Thats what I have seen in several videos of it. Some argue that can't happen, but the wear pattern on the cam lobe of bad CP4's tells a story itself. If the pump is THAT sensitive the particles of debris 3 microns or less destroy it, well the pump is poorly designed..IMHO of course.
 
NDanecker said:
Its not so much about clean diesel but pure diesel. Water containments play a huge part also. With this pump design, assuming 26k rail pressure and pump plunger diameter of 0.25" diameter the roller can see ~ 5,000 lbs of force spread over an extremely small area. Is it exceeding its tensile strength? Guessing so since we are seeing a higher than normal failure rate. If the roller assembly does rotate in its bore as the video suggests it can do then it will def fail. Remember its diesel fluid and not oil which has better lubricating properties that help reduce friction, heat build up, etc.

EDIT: In addition, if you run the new pump without 100% full of diesel it has a much higher rate of failure as it requires diesel for lubrication. Are people making sure they prime the fuel system after a filter change before starting the motor? I remember when I changed my filter on my CP3 trucks I just cranked it until it started which you could get away with on the old CP3 pump. I don't believe that is the case with the new pump.
Click to expand...
I used to prime the filters on my 16 RAM 2-3x....You can bet I'll prime these filter 5-6X before I try and start it up !!!! LOL
 
Brutal_HO said:
LOL, I went all the way to the final checkout button and was too chicken to see what would happen if I pressed it. The tax was $50K.
Click to expand...

I have heard the first 50 customers that try get their order for free. Everyone after that though........ You have to ask yourself, Do I feel lucky today.
 
leeroy300 said:
any more info from Ramcares?
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I won't speak for @RamCares but considering it's been just over two weeks since their initial post I'd say give it another week or two before we get the pitchforks out. If they didn't mention anything to us until everything was ready to go we would complain about not having enough insight into the process. If they tell us before everything is ready we would complain about it taking too long.

Not calling you our @leeroy300, just sharing for the comments that are sure to follow.
 
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