2250 Carnage Pictures

[Rawze]

(04-09-2017 )doarmihai Wrote:  https://youtu.be/zbOzX_OFDIg

Nice video, but is not for ISX.

[Billdozer2]

(04-09-2017 )Rawze Wrote:  Nice video, but is not for ISX.

That's what I was thinking too. I'm like "This isn't an ISX fuel system."

What Rawze is saying is true. I did this leak down test about a year ago and found that my fuel pressure dropped maybe 100 psi in a minute. If yours is dropping 11,000 psi or what ever you said, you have a major issue. I'm really curious how the engine would run with that kind of leakage.

As far as the fuel system bleeding off, with my engine off, my fuel pressure sits around 5,000 psi. I've left the truck for a week and it is still at 5,000 psi. My truck fires right up, usually just after one engine revolution. The fuel doesn't continuously bleed off after the truck is off, at least not on mine.

[Rawze]

(04-09-2017 )Billdozer2 Wrote:  

(04-09-2017 )Rawze Wrote:  Nice video, but is not for ISX.

That's what I was thinking too. I'm like "This isn't an ISX fuel system."

What Rawze is saying is true. I did this leak down test about a year ago and found that my fuel pressure dropped maybe 100 psi in a minute. If yours is dropping 11,000 psi or what ever you said, you have a major issue. I'm really curious how the engine would run with that kind of leakage.

As far as the fuel system bleeding off, with my engine off, my fuel pressure sits around 5,000 psi. I've left the truck for a week and it is still at 5,000 psi. My truck fires right up, usually just after one engine revolution. The fuel doesn't continuously bleed off after the truck is off, at least not on mine.

Actually, the electric fuel pump will build roughly about 250+ psi or so with the key on and that is enough to fire the engine most of the time even if the rail has been bled to 0. If someone's fuel rail is leaking badly and it is mostly the bypass valve, and not injectors, then it may have very little symptoms. Still not good for it because it overworks the pump all the time causing unnecessary wear, lowers fuel mileage, and like any kind of hydraulic leak, heats the fuel unnecessarily.

If it is an injector, it can be subtle if it is not too bad, or be bad enough to cause hard-starts. A start-up that as it crosses the cylinder with excess fuel in it from injector leakage that causes a hesitation in rotation of the engine for just a very brief moment as it is cranking before it fires. Almost feels like a battery that is weak as it first starts to turn over sometimes. I have even seen an engine with an injector leaking so badly that it caused hydra-lock due to all the fuel dumping into a cylinder while it sat. Thats nothing to play with. That kind of problem can bend rods and cause some serious damage as it start to get real bad.

[halfpint]

Ok so I have a cm2250 with the old style pump, 3 plungers. Can I get a rebuild kit for it, or will I have to change to the new style 2 plunger pump?

[scottydogtruck]

(04-12-2017 )halfpint Wrote:  Ok so I have a cm2250 with the old style pump, 3 plungers. Can I get a rebuild kit for it, or will I have to change to the new style 2 plunger pump?

Smart money says to replace the 3 plunger with the 2 plunger pump itself..don't rebuild.....will save you loads of headache in the longrun. Do this like yesterday!!!!!

[JMBT]

Halfpint: I just replaced my 3 cylinder with the new 2 cylinder. My 3 cylinder was still operating perfectly but had started to leak a bit of fuel from the weep hole in the gear pump, (which according to quickserve means the internal seal between the fuel pump and gear pump has failed) I took it off the truck and popped the head off and it was perfect inside, ceramic plungers, cam, and rollers all looked new, even at 580K. So I wondered the same thing, can I get an upgrade kit to the steel plungers for this pump? I talked to 3 Cummins dealers and all of them told me no. So instead of several hundred for new plungers, tappets, and seals, I got shafted for $4400 in parts (new pump, mounts, lines, gaskets, and sealing washers) and that was just parts, with my brother and I doing the work!
Now one of the guys on the forum had the idea of mic-ing one of the old ceramic plungers and then a new steel one at Cummins to see if they are interchangeable, but then I would still have needed an old style gear pump to deal with the leaky internal seal. Cummins says no parts for the 3 cylinder are available any more and I just flat out didn't have the time to dick around with investigating further.
If I had, had more time I would have investigated more and rebuilt this 3 cylinder if the steel plungers were interchangeable, and if I could have located a gear pump. It would have been a lot better then getting raped for $4400! I know some on here would disagree, but I don't think the 3cyl has any other inherent problems then just the ceramic plungers so in my mind if you have the time to do some searching, and you are doing the work yourself I think upgrading the 3cyl would be the way to go, and DEFINITELY a much more cost effective option. Just my opinion.
Another option: one of the guys on here had bought a used two cylinder, all two cylinders are upgradeable per cummins, and put new internals in it. Still a sh!t-ton cheaper and with the same outcome.

[Hammerhead]

JBMT & halfpint;
I cannot find parts listings to do a crossover or comparison, but from what I'm observing (2) 4327258 HD XPI B&P SERVICE KITs will install into the head of a Three Cyl Two Piston pump, replacing the ceramic plunger with steel and a new plunger barrel...effectively eliminating the ceramic failure parts.
This kit includes the following as a complete assembly(s) that installs into the head. Two are required;
3867651 O-ring Seal
4984382 Sealing Washer
4984182 Pump Tappet Barrel
4307336 Pump Tappet Plunger
4928605 Compression Spring
2872626 Spring Retainer

This will not rectify the internal seal leaks JBMT notes, and may be a throwing good money after bad situation for halfpint if you replace this Assy and shortly after develop the same seal leaks as JBMT. As stated by JBMT, this may be a "cheaper" option for the time being to remove the time bomb of the ceramic plungers until you can save the $$ for a new 2cyl pump or source a used one.

Remember, I'm completely full of it...verify what I have stated before taking the plunge...pun intended!

[JMBT]

Hammerhead: Thanks, I wish I had, had the time to research this before I bit the bullet on the new setup. Had a customer nipping at my heels... I may still give it a try though old pump is sitting in my brothers shop, while I decide whether to rebuild it for a spare and try to find a good used gear pump, or take it out back to the scrap pile! Halfpint: there you go, if you don't have anything leaking, I would take that sucker apart, inspect it and if all looks well, rebuild with the parts above!

[Hammerhead]

(04-13-2017 )JMBT Wrote:  Hammerhead: Thanks, I wish I had, had the time to research this before I bit the bullet on the new setup. Had a customer nipping at my heels... I may still give it a try though old pump is sitting in my brothers shop, while I decide whether to rebuild it for a spare and try to find a good used gear pump, or take it out back to the scrap pile! Halfpint: there you go, if you don't have anything leaking, I would take that sucker apart, inspect it and if all looks well, rebuild with the parts above!

No problem.
I only know about the part kit by accident. When he decided to double check his pump, I told my buddy to get a set of steel plungers just in case so that we had them if needed, and we'd return them if not. Cummins told him of this kit and he's like me, sometimes it just makes more sense to change associated parts while you're in there so he got the kit instead. His reasoning was "If the plungers were ceramic, then putting new plungers into used barrel bores didn't make sense. If the plungers were steel and were sticking, as per procedure, we'll need the barrels anyhow."
I agreed. But even with the kit part number, I still cannot find the kit on Quickserve! Add to that, the procedure specifically says NOT to remove the tappet barrel from the head, yet the kit comes assembled and requires removal and reinstallation. This pisses me off, because without the procedure, what do you torque it too? I had to mount the head in the vise and had to "tap" my 1-3/8" wrench with a hammer to break the barrels free. I had to resort to G&FT torque spec, and I do not like to do things that way.

If anyone comes across the procedure and correct torque spec for the tappet barrels into the head, I'd sure appreciate the info, the dealer that supplied the kit couldn't provide the torque spec, they said to bring it in and they would do it...I'm still laughing.