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I have a customers 01' IH4700 with a DT 466E that is building alot of coolant pressure. truck was brought in for CEL being on. other tech stated it was over heating however it was pushing out coolant rather than boiling over. truck did not reach 140 degress and was pushing coolant out around the resievour cap. tech said the air compressor 'must have been bad allowing air pressure to build with in the cooling system (anti freeze cooled air comp.) I reaplaced the compressor only to find the same results. I love being the low guy on the totem pole, did not really get a chance to troubleshoot it just was told to do the grunt work. what should I check? as far as I know the other tech has flush the radiator and thats it.
 

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A failed injector tube can cause that, check for combustion gasses in the coolant, a positive test warrants further tear-down of the engine until the cause is isolated.
 

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A failed injector tube can cause that, check for combustion gasses in the coolant, a positive test warrants further tear-down of the engine until the cause is isolated.
On the the E model and newer they are called cups not tubes:)

I agree with john it could be a cup or a head gasket. You might want to let the other tech know that the easy way to check if it the air compressor is just pull the air discharge line off of the compressor then run the engine. If it still builds pressure then its not the compressor if it quits then it the compressor.
 

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Check for coolant in the oil. Liner o-ring failure are common with that series engine. Injector cups failing are rare. Failed injector cups allowing compression into the cooling system will be associated with other things such as a skip, diesel in the cooling system. I would T in a pressure gauge, replace the thermostat and or check it for proper operation. Then road test. The cooling system pressure should be what ever the cap is rated for. (15psi)
 

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Check for coolant in the oil. Liner o-ring failure are common with that series engine. Injector cups failing are rare. Failed injector cups allowing compression into the cooling system will be associated with other things such as a skip, diesel in the cooling system. I would T in a pressure gauge, replace the thermostat and or check it for proper operation. Then road test. The cooling system pressure should be what ever the cap is rated for. (15psi)
The guy has already changed the air compressor so he has seen the oil if it has water in it even an idiot can see that somthing is wrong there. Yes the cups failing is rare but it does happen and I had one about a month ago with no other problems but compression in the coolant. The thermostat will cause a over heat but not over pressure in the cooling system before the truck even gets to 140. Also of the top of my head I'm pretty sure the 01's has 10 psi caps.
 

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The guy has already changed the air compressor so he has seen the oil if it has water in it even an idiot can see that somthing is wrong there. Yes the cups failing is rare but it does happen and I had one about a month ago with no other problems but compression in the coolant. The thermostat will cause a over heat but not over pressure in the cooling system before the truck even gets to 140. Also of the top of my head I'm pretty sure the 01's has 10 psi caps.
I get idiots in all the time that think they need a headgasket when in reality they have a failed liner o-ring, scuffed the piston and cracked the liner and are putting compression into the system through the liner. There will be coolant in the oil - gallons of it and they still have no clue. So don't play off the "even an idiot" card. You need to check everything yourself - period. You see virtually no oil on a DT when changing a compressor so that point is not valid. There are several different caps available for an 01 model depending on the radiator set up, and truck model.

You seeing water droplets on the dipstick?
 

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If it popped the HG, there WILL be overheat codes, if it's a liner there often are no codes.
 

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I have a customers 01' IH4700 with a DT 466E that is building alot of coolant pressure. truck was brought in for CEL being on. other tech stated it was over heating however it was pushing out coolant rather than boiling over. truck did not reach 140 degress and was pushing coolant out around the resievour cap. tech said the air compressor 'must have been bad allowing air pressure to build with in the cooling system (anti freeze cooled air comp.)
Air compressor is a possible cause, but you need to prove that a high-dollar item has failed before replacing.

Quick and easy test; bypass coolant flow by temporarily connecting air compressor inlet and outlet coolant hoses. Start and run engine long enough to replicate your problem... 1. If coolant is still over-pressurizing, air comp is not the problem. If coolant now has normal pressure, air comp is problem.

I reaplaced the compressor only to find the same results.
That makes for a disappointing days work; this takes all the fun out of pulling wrenches:(

I love being the low guy on the totem pole, did not really get a chance to troubleshoot it just was told to do the grunt work. what should I check? as far as I know the other tech has flush the radiator and thats it.
The benefit of being the low guy on totem pole (doing as you're told;) means that you're NOT the one who called the air comp w/o testing. You get to learn from someone else's mistake;)

Next of course, you should be reading up on basic cooling system operating theory.

He flushed the radiator to cure coolant pushing out past the cap? you have a very patient and understanding customer?!?

BTW- your description sounds like a textbook example of a leaking fire ring in the head gasket; verify with block chek, or other exhaust gas detecting fluid.
 

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Check for coolant in the oil. Liner o-ring failure are common with that series engine. Injector cups failing are rare. Failed injector cups allowing compression into the cooling system will be associated with other things such as a skip, diesel in the cooling system. I would T in a pressure gauge, replace the thermostat and or check it for proper operation. Then road test. The cooling system pressure should be what ever the cap is rated for. (15psi)
Liner o-ring failure will NOT cause over-pressurization of the cooling system... liner wall cavitation can.

I have pulled several cracked brass cups, the stainless however are much more robust, and unlikely to cause over-pressure cooling system in either case.
 

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Liner o-ring failure will NOT cause over-pressurization of the cooling system... liner wall cavitation can.

I have pulled several cracked brass cups, the stainless however are much more robust, and unlikely to cause over-pressure cooling system in either case.
Didn't say a liner o-ring would cause pressurization of the cooling system. But when the driver has an oring fail and keeps driving, the piston will scuff and can crack the liner - this will then allow compression to enter the cooling system. This will show up as a low temp reading (lack of coolant in the system) and over pressurization (compression directly into the cooling system).
 

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I have seen a lot of engines toen down and never a cracked liner from a scuffed piston. Cracked BLOCKs from excessively low coolant, yes more than once.
 

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What is your question? What don't you understand about the post?
This scenario happens more than you think on the 466e. The last one we had like this came in with a gaping hole in the radiator from the excess pressure.
Sorry, for that to happen, the rad cap would have needed to be almost welded or glued shut. The industry has a problem with Rad caps NOT holding rated pressure - leaking off much lower than the rated pressure. We do not have a problem with caps sticking closed.

Now, if you have a radiator designed for a 7psi cap and some idiot puts a 15 psi cap on it because the truck is pushing water out, well all bets are off.
 

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What is your question? What don't you understand about the post?
This scenario happens more than you think on the 466e. The last one we had like this came in with a gaping hole in the radiator from the excess pressure.

So....... you witnessed an engine that; scuffed a liner to the unimaginable extent that it split the liner wall open, and it then pressurized the cooling system to a pressure that blew the side out of the rad?

.......I have no comment for that statement
 

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What is your question? What don't you understand about the post?
This scenario happens more than you think on the 466e. The last one we had like this came in with a gaping hole in the radiator from the excess pressure.

Hold on, i do have a comment;

Let's reverse engineer this mysterious engine failure you're referring to. I'm not suggesting this was the real sequence of events, but it makes better sense to me.

Let's pretend the truck was driving down the road and ran over a large widget... this widget then became an under-chassis projectile and struck, then busted the radiator tank... the cooling system excreted all of its fluids onto the road... the cylinder overheated and scuffed the liner... and then the liner cracked open before the engine seized ...or the driver noticed the severe, HEAVY engine knock.

...just thinking out loud.
 

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.....
LoL! Just what I was thinking!
 
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