Isx injector cup TSB

Humble pie

Another Acert bites the dust
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Welp my radiator is slam full of fuel. There is known issues with isx injector cups. That said there are two TSB out one for SOHC and one for DOHC. I have a cm870 with the DOHC. They have an updated lower injector O ring for this one. Does anybody have experience with this repair? Truck just needs to last another 4 or 5 months. @pushbroom ? Anybody?
 

Oxbow

Well-Known Member
Supporter
Welp my radiator is slam full of fuel. There is known issues with isx injector cups. That said there are two TSB out one for SOHC and one for DOHC. I have a cm870 with the DOHC. They have an updated lower injector O ring for this one. Does anybody have experience with this repair? Truck just needs to last another 4 or 5 months. @pushbroom ? Anybody?
Wasn't the new Freightliner going to be in next month?

Sorry to hear about this HP, hopefully the solution isn't too pricey.
 

Humble pie

Another Acert bites the dust
Supporter
Damn the luck.

I've read a fair bit about injector cups on Cats. There was a guy on TTR that could mill the seats with the engine in the truck. Not sure if that's what you need or just replace the orings. I'm curious as to what the repair will be.
Far as I know Cummins heads have to come off to replace injector cups. They have this new fix, but it apparently doesn’t work all the time
 

pushbroom

Goldmember
Supporter
I have done alot of the injector sleeve repair on the 2250/2350 for coolant in the fuel. Pop the injectors out and drive in a stainless ring that expands the top of the injector cup so it seals again. Success rate is 95% or better. It is very critical to install the ring to the proper depth, i think alot are installed to shallow and not measured leading to unsuccessful repairs.

I have not done the repair on the twin cams for fuel in coolant yet. Looks like a larger o ring on the injector to make up for the injector cup not sealing.

According to cummins the cups are still not serviceable, however i think monaco or apex makes a tool to remove and install them? No experience with it however.

It it would take is a weekend and a set of injector o rings to fix it up. Should be fairly easy task
 

Humble pie

Another Acert bites the dust
Supporter
I have done alot of the injector sleeve repair on the 2250/2350 for coolant in the fuel. Pop the injectors out and drive in a stainless ring that expands the top of the injector cup so it seals again. Success rate is 95% or better. It is very critical to install the ring to the proper depth, i think alot are installed to shallow and not measured leading to unsuccessful repairs.

I have not done the repair on the twin cams for fuel in coolant yet. Looks like a larger o ring on the injector to make up for the injector cup not sealing.

According to cummins the cups are still not serviceable, however i think monaco or apex makes a tool to remove and install them? No experience with it however.

It it would take is a weekend and a set of injector o rings to fix it up. Should be fairly easy task
Thanks man. I’m gonna pop them out tomorrow and make sure I don’t have any cracked cups and try the O-rings. It may be Monday before I can get them. Most of the parts houses around here are closed on Saturday
 

pushbroom

Goldmember
Supporter
Thanks man. I’m gonna pop them out tomorrow and make sure I don’t have any cracked cups and try the O-rings. It may be Monday before I can get them. Most of the parts houses around here are closed on Saturday
I wouldn't be surprised if no one carried the special lower orings in stock.
I like the fleetguard coolant system restore, may need 2 jugs. Drain the coolant first before you pull the injectors.
Might as well do a top set. Truck will run like crap when it starts from all the air in the system, just rev it up and it will calm down. I think they might have a newer priming procedure so they dont snap and crack as bad at first startup.
 

Humble pie

Another Acert bites the dust
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I wouldn't be surprised if no one carried the special lower orings in stock.
I like the fleetguard coolant system restore, may need 2 jugs. Drain the coolant first before you pull the injectors.
Might as well do a top set. Truck will run like crap when it starts from all the air in the system, just rev it up and it will calm down. I think they might have a newer priming procedure so they dont snap and crack as bad at first startup.
I meant to ask what you liked to flush the system. I know some people will just use simple green or some other kind of degreaser
 

Mike

Well-Known Member
Staff member
# 6 Injector lower o-ring was split in half. #2 Injector lower o-ring was pretty rough looking too. I ordered new O-rings and the TSB o-rings they should be in this morning.

part numbers for the updated o-rings Is 5440257
Did you end up getting anything special to flush the cooling system out? Dawn detergent worked well for me, but I seen you asked about a specific cleaner.
 

Humble pie

Another Acert bites the dust
Supporter
All of this begs the question: Are these o-rings an item that ought to be changed out periodically, say every 200,000 miles or so?
Shouldn’t be. As I said before 3 injectors had different color o rings. If I remember right I had sourced injectors from two different places. I think 3 came from kenworth and 3 came from turbo diesel and electric. I’m willing to bet those three had aftermarket o rings.
 

Humble pie

Another Acert bites the dust
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Truck is back together. Flushed the radiator it seems to run a little smoother. I had picked up a slight miss at idle that seems to be gone. Hope it takes care of it. $215 in parts and about 8 hours labor and it’s done. Not nearly as bad as it sounded.
 

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