CM2250/CM2350 Fuel Pump

[SquareOne]

Ok guys, didn't see the need to beat on a dead horse and start a new thread on this. Finally got around to breaking into the fuel pump and inspecting and replacing the tappets (rollers)...

- Just as a refresher, its a cm2350 with a 2/16 build date.

From start to finish, took me roughly 2.5hrs. This is my first time doing this and I'm particular about inspecting everything as well as putting everything back its factory location - i.e. clips, zip ties, or any other securing mechanism. I'm sure people who are familiar can easily shave off 30-45min. BTW, this was done on a 13' Cascdia which is a PITA to say the least (Rawze, FBK...you know what I'm talking about lol).

I was pleasantly surprised to see the condition of the items that were removed. This pump has about 294k miles currently and after reading horror story after horror story, I did not want to sit on my a$$ with this issue. The pump didn't have any broken paint on any of the bolts, so I don't think it was opened up. I also called Cummins (before purchasing) to see if there was any warranty work done....which according to them, there wasn't.

So, inspected thoroughly the condition of the pump bores, cam, the steel plungers (along with smooth movement), springs and contact surfaces, as well as the effortless movement of the new tappets once installed into the pump. (Make sure you orient the alignment pins correctly before installing the tappets. Check for the free movement once installed and be sure they will not rotate. No binding should be felt. Be sure they are fully seated in the bores) What was interesting was that the old tappets were actually the new design (again this is a early 2016 build date). They most likely could've went much further as they seem to be in great shape for the miles ...I'm sure those who do this on a regular can confirm the condition.

Everything went back together smoothly and she fired up with no issues so far - fingers crossed. Point being, if you're on the fence about knocking this out, you need to jump off and get it done. Take your time and it should be nice and straight-forward. Between this site and QuickServe, you will have all the tools you need to get it done. Hopefully these new tappets will give me another problem free 300k!


Here's the PN's I used:

4359134 - Tappet (x2)
2872513 - Headgasket
3963990 - Sealing washer (x2)
3963988 - Sealing washer (x2)


* These are a few pics of the rollers that were removed. If anyone has any questions, please don't hesitate to PM me.

         

[jimeneztrans84]

You didn't install new plungers?

[SquareOne]

(06-22-2019 )jimeneztrans84 Wrote:  You didn't install new plungers?

No...the only way to get the barrel/plungers is to buy the entire head now with them already installed. Seems like someone decided it was more profitable that way.

I inspected the spring and mating surface (per Cummins service procedure),as well as the plunger movement and all was fine. Also, one of the main contributors of this site does not replace them unless there is a prior fueling issue being repaired.

[jimeneztrans84]

They sell the plungers seperate. Even if they are steel they still fail and are supposed to be switched out at certain mileage from what I've read here on forum. There's videos showing how to replace them.

[SquareOne]

(06-22-2019 )jimeneztrans84 Wrote:  They sell the plungers seperate. Even if they are steel they still fail and are supposed to be switched out at certain mileage from what I've read here on forum. There's videos showing how to replace them.

Barrel / Plungers are sold as a matched set. Must be replaced together. The only ones I could find were from a seller on ebay who claimed they bought them and didn't use them....didn't want to go that route. I tried multiple different avenues and could not locate them. There were a few spread throughout the country and apparently couple in India. The few dealers that did have them would not get off of them. The way to purchase them now is with the whole head assembly.

- If you happen to find them elsewhere, please let me know as I couldn't locate them individually.

- Yes, apparently the steel ones do fail as well. Not sure what happens first, the plunger or the roller....maybe one goes because of the other...not too sure. I was just informed by a very well known/respected engine builder (from this site) that they do not replace the head (which is how you have to get the barrel/plunger assemblies now) unless there is a fueling issue.


.....actually, jimeneztrans84, I think I was using the part number you provided on a post awhile back about the fuel pump situation.

[SquareOne]

After seeing one in person opened up, I would like to know how they actually fail. Of the carnage pics i've seen from this site and what I've read, it looks to me like the rollers and cam lobes were oil starved...just an educated guess. If you have an engine that's heavily sooted, wouldn't you think that it would starve the pump of lube oil if the passages were even slightly restricted?

I mean, the plungers failing.. wouldn't that strictly be a fueling issue? The movement of the plungers is very little so even if they were to get stuck in the extended position, it seems like it would starve the engine for fuel...not destroy the cam/rollers. The spring will keep the roller contacting the cam at all times so a plunger stuck closed should also not result in destruction. Maybe when the ceramic ones failed, they shattered and thats where the damage started? I would just like to understand this more.


This is all just an assumption as I have no base to what I'm saying other than what I observed when opening the fuel pump up. Maybe the engine builders can chime in with there thoughts? What was the condition of the barrel/plungers when a fuelpump failed? Seems like they would still have to be pumping fuel in order for the engine to run long enough to tear itself up?

- Has anyone seen the same fuel pump failure with the updated tappets? Makes me again wonder if majority of the issue was with the brass roller pins in the older tappet design? As the pin fails it would certainly stop the roller thus dragging it along the cam lobe....we all know what friction does, and in a hurry. It seems like that would make sense. If the roller and cam lobe was substantially damaged (as in littering the engine with debris), I would imagine the erratic movement of the tappet would then damage the plunger....so it would appear as if the plunger was the culprit when it was actually the failed roller pin that started it all! - Dunno...sounds like a decent theory lol

[Mattman]

Curious how many dollars do they want for the pump head assembly?

[Lonestar10]

something around 2-3 grand if i remember correctly

[SquareOne]

1500-1800 are the prices I found