I like Superduty's theory on tolerances. This isn't the first winter we have discussed leaking CP3's....and these threads always seem to pop up around December. Search for last year's leaking CP3 threads on here and TDR and notice the date. I like to think that things get cold and shrink, and the CP3 has such high pressures inside, a little seeps out past gaskets and such. For me, a pressure box compounds the issue.

For most of us, I don't think it will ever hurt anything. I do wonder if the new CP3S has the same issue though. I do remember reading that the CP3 has a weep hole (like on a water pump), and on the newer CP3S, the weep hole is relocated to the top, so leakage won't be as noticeable, or noticeable at all. I don't know that to be fact.

Those that suffer side effects or have large amounts of fuel leaking may have an actual "problem" inside and need a new pump.

 

I just got back from the dealer. I SHOWED the tech the leak, he called STAR, and...........TA DA!! - they have ordered me a new CP3 injection pump. Go figure...

He said the part is coming from L.A., so it won't be here for a few days. He said I can continue to drive the truck.

 

whats the exact name for the CP3 so I can tell my dealer to install a new one of those as well? Along with the lift pump!!!

 

"I like Superduty's theory on tolerances. This isn't the first winter we have discussed leaking CP3's....and these threads always seem to pop up around December. Search for last year's leaking CP3 threads on here and TDR and notice the date. I like to think that things get cold and shrink, and the CP3 has such high pressures inside, a little seeps out past gaskets and such. For me, a pressure box compounds the issue."

The high pressure fuel is limited to 3 pumping chambers. If the plungers/barrels of those chambers are really worn, fuel will get back to the common area via leakage, but it will be at the common area pressure, which is 80 to 180 PSI.

"For most of us, I don't think it will ever hurt anything. I do wonder if the new CP3S has the same issue though."

Do you guys have a part number for that new pump ? Bosch or Dodge. I haven't heard a thing about it.

"I do remember reading that the CP3 has a weep hole (like on a water pump), and on the newer CP3S, the weep hole is relocated to the top, so leakage won't be as noticeable, or noticeable at all. I don't know that to be fact."

The CP3 has a cascade overflow valve, which does have a pin hole in it. Actually, the hole is smaller than a pin. It serves to keep the pump internally pressured when it is returning fuel. A spring loaded relief valve would have been a better way to do that rather than the pin hole.

"Those that suffer side effects or have large amounts of fuel leaking may have an actual "problem" inside and need a new pump."

Seals are usually pretty reliable. I only know of 3 reasons why they fail. Exceed design pressure. Shaft clearance grows and the seal now has to seal a bigger gap. Or the seal drys or gets burnt.

I think the last one is the issue.

Starting the truck when it is really cold with cold fuel could cause higher pressures in the CP3, but it shouldn't be enough to blow a seal. The FCA controls the internal pressure, which also controls the rail pressure. 80 to 180 PSI internal pressure according to the 05 shop manual.

 

Did some looking, and it appears like your 05 should already have the updated pump (so much for the new pump may not leak idea). I'm not sure on the numbers. It is all a little sketchy. Something like this:

Dodge Part #s
5086765AA – 2003/2004 CP3
5104877AA – 04.5+ CP3S3

I also hear that if you try to get an 03/04 pump, it automatically updates the part number to the CP3S3.

 

I found this:

5086765AA - 2003 CP3 dealer net $665
5104877AA - 04.5+ CP3 (High output) dealer net $780
R5104877AA - Reman. Dealer net $1000 less core of $360.


So... dealer cost on these things is way south of $1000. Keep that in mind if the dealer wants to sell you a new one.

BTW: The ISL uses a CPx pump as well. Might be worth looking into what it is.

 

So as anyone had an issue with the newer CP3S pumps leaking????

 

I also thought my box had had ill effects on the pump but there are way to many Stockers crapping out!!!! So the pressure boxes are not the problem.

 

Took mine in this morning. They said they had to order a pump. Mine only has 7,400 miles on it and no mods. They said they will call when it comes in. Oh well

 

I just got back from Woodhouse NE and had a new CP3S put in. I got about 1 hour from home and stopped at a gas station to check things out. Guess What????

It was leaking oil about 1 qt every hour of driving. When they put in the new pump the must have F%&K up. It looks like it is leaking right in front of the pump, and of course they did not have enough time for me to go back up there to have it fixed. They said they closed at 5:30, and I would have gotten there about 5:00 or 5:15. I guess they had no time to fix there mess up.

I have no luck at all. I drove 3 hours so I could have my truck to go on an ice fishing trip by Monday, and I now I am F$%&k#$ again. If I did not love this truck I would have taken it to the junk yard for sure. 2004.5 Cummins 600 with 24K on it and over $2000 in work already. All paid for by Dodge. It is a good thing that I bought an extended warranty because it looks like I am going to need it at this rate. I must say I am getting tired of defending this thing to my Ford and Chevy buddies. Just when I have them about converted this happens. When will Dodge put quality parts around the best motor out there.

Sorry about this post I am just venting a little because I just got back home from this day of hell.

 

This part has nothing to do with Dodge. It is a Bosch-made part on the Cummins motor. So, can't blame DC for this one.

It DOES suck, though. And thanks for the heads up.

 

It is true the the pump is a Bosch, but DC chose to use there pumps. Aren’t there any other pumps that are better? I am just so tired of having my truck down. I bought a diesel mostly for reliability. I have never had this much trouble with a new gas truck. Granted I will never go back to a gas truck again.

By the way, Woodhouse is going to come and pick up my truck today and get it fixed. I will let you all know how that comes out.

Have a good x-mas

 

R5104877AA - Reman. Dealer net $1000 less core of $360.
Ah hah! Thanks Superduty. Now I know I have a used remanufactured piece of junk installed on my truck. R5104877AA is the part number on my invoice. This would appear to be the answer to the question if anyone has had problems with the CP3S (HO pump). Why else would remanufactured CP3S be available and used as replacements as on my truck? Tick, tick, boom. Sounds like they are timebombs just waiting to explode. I can hardly wait until I have to go in for the third pump replacement.

 

Just checked my invoice and it is also the remanufactured pump. Not really overjoyed learning that tidbit. And they want to build brand loyality?

 

"It is true the the pump is a Bosch, but DC chose to use there pumps. Aren't there any other pumps that are better? I am just so tired of having my truck down."

The CP3 (and its cousins, the CP1 and CP2) are used in lots of engines in NA and Europe without any problems. Duramax, QSB, QSC, QSL, ISL, Mercedes, all use the CPx pumps. Without any problems. Especially seal leakage problems.

Maybe the problem isn't the CP3... maybe it is the... LIFT PUMP ! Get it ? Remember the VP44 issue on the 2nd gens ? VP30s are used in VW diesels without ANY problems. The common denominator in the Dodge failures is the LIFT PUMP.

Repeat after me. I'll fix my lift pump BEFORE it fails. I'll fix my lift pump BEFORE it fails. I'll fix my...

"I bought a diesel mostly for reliability. I have never had this much trouble with a new gas truck. Granted I will never go back to a gas truck again."

I know. Its a shame. A beautiful, outstanding diesel engine brought to its feet by a $100 lift pump. 90% of the trouble you will ever have with a diesel engine has to do with the quality and volume of fuel you feed it. Put a good pump on your truck and you'll never have another problem.

"By the way, Woodhouse is going to come and pick up my truck today and get it fixed."

The only way to fix these trucks is to put a good lift pump on them and a new CP3. I'm fairly certain that people have been running their CP3s without a decent lift pump which has wrecked them. Conversely, people/dealerships can keep replacing the CP3s all they want, but if the lift pump isn't working it won't do any good. They will keep failing. You need a good lift pump and a good CP3.

BTW: I don't think there should be too much wrong with a rebuilt CP3. However, if it wasn't cleaned out properly or if the stock filter is passing dirt the cascade overflow valve will plug and the pump will blow seals. I'm assuming they put new seals in these pumps and they tested them.

If I had a truck that was blowing CP3 seals, ie if I was a dealer, I would pull the cascade overflow valve and check that it was working properly and the orifice wasn't plugged.

Whew ! All this and I don't even own a Dodge !

Good luck.

I'll shut up now.