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Deleted EGR and now have questions about refilling coolant. NEED ADVISE!

8K views 43 replies 11 participants last post by  DIRTYMAX9786 
#1 ·
I deleted the EGR and replaced the factory up pipe on my 2014 2500HD LML. I did all the work myself and yes it was a pain in the ass! Took me 2 full days! But I got everything back together and it all seems to be working fine. I refilled the coolant per the instructions in the duramax supplement book. But today I went by my local mechanic and to talk to him about what I did and he asked me if I ran a vacuum on the coolant system to remove the air?? Well of course I didn't because I don't have that tool and he told me that because I didn't do this I could cause major problems with my engine specifically a blown head gasket. And that I also probably ruined the two brand new thermostats that I just installed. He said the t-stats will go into a "fail safe" position and stick open when the is air trapped in the lines and the coolant gets too hot. So for $250 plus parts (new t-stat, more coolant) he could run the vacuum on the system and replace the thermostats and hopefully no damage was already done. My issue is that I haven't read in ANY of the EGR delete instructions or in any threads that you have to run a vacuum on the coolant system. I know its a faster way to get the air out instead of running it with the cap off and adding as needed, but is it something that HAS to be done to avoid damaging my engine?? Any help will be much appreciated. Thanks, Wes
 
#2 ·
I think he's trying to scam you... Check out this video on how to properly bleed the duramax cooling system, skip to 4:45
https://youtu.be/qjXDifpGGrs
 
#3 ·
The lml doesn't have a bleeder screw on the thermostat housing like the earlier models. At least not to my knowledge. But the duramax supplement has a detailed instructions on how to properly add coolant. The short version: Fill system to the seam in the surge tank, run truck until it reaches 195 degrees with the cap off, fill it to the min mark, and repeat if necessary .
 
#4 ·
Just to add to this - Once you have done the OEM process, I usually park on a hill, nose up, and let it idle for 10 mins or so. Over half the time, I get a burp during the uphill stand, and have to add another 8-10 oz of coolant.

No special tool required.


GL
 
#8 ·
Well after reading everyone's comments and talking to anot her mechanic I thought I was good to go. So I drove approx 80 miles today to see if it was going to hold coolant and when I got home my low coolant light came on and I found coolant sprayed all over the passenger fender well. The overflow side is full and the other side is almost completely empty?? Starting to think maybe he was right about needing the vacuum?
 
#6 ·
This is a little differant than the duramax supplement instructions but pretty damn close to what I already did. Now my one mistake is that I only did this "process" the first time I had to add coolant to the system. The second time I added coolant I was an hour away from my house and I did it in a parking lot. Me and my family were at a pumpkin patch and when we went to leave I checked my surge tank and it was almost completely empty so I just filled it up to the min line and drove home. I did not go through the steps that I probably should have. And it did spit out a little coolant on the way home but not much. But it never overheated or even went past 210.
 
#7 ·
And now I really can't even use these steps because the coolant is past the "middle seam" and if you try and idle it up for 5 min it will overflow out of the fill hole. So after driving it for a day around town I added just a little more (maybe 2 cups) just to top it off. And I did this after it sat all night and was cold.
 
#10 ·
I don't recall anyone else posting here about needing a vacuum machine to do a coolant refill -- but it sure sounds like there is something wrong with your engine or method
 
#11 ·
The one last thing I'm gonna try before bringing to the mechanic is getting a new cap for the coolant tank. Makes sense that if it's not letting the pressure off of the tank that the tank would build up too much pressure and push the coolant out of the overflow? This is my first diesel so I'm really not sure how those caps work but I think that's the basic principle.
 
#13 · (Edited)
After you've worked on something after loosing coolant, bring it up to level and run the engine until operating temperature, check level.
After this, I've always just filled the coolant tank about 1"- 1 1/2" above the fill line, then drive.

Check it later if it's still good then let it set overnight, if it needs a little add it, if it doesn't then your good.
If the level is a little high then suck some out (I'll use a baster) or just let nature take its course.
It's not really that technical of a procedure, this has worked for me for over 50 years and still works.
 
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#14 ·
Were you careful to not get any fluid on the 'passenger side' of the tank before getting it up to temp?

Did you get it up to temp with the cap off the tank?


This system is NOT like the ones you are used to (and not like any other diesel that I have owned/maintained/tested).
 
#19 ·
Yes I followed the instructions and let it get up to 195 degrees with that cap off. And I was letting it idle yesterday with the cap off and I did notice a steady bubble coming up to the top , is this normal or should I be letting it run like that until I see no bubbles? I let it run for a good while and that bubble would still come up about every 5 seconds I thought maybe it is supposed to do that since I was told it is a "gassing" system. And after a day of running it and still having issues I got the refill instructions from the dealership which were a little differant than the ones in the manual. They said to idle up the engine to 2500 rpms until it reached operating temp and then to let it idle, add fluid, then repeat one more time, then top off. But when I was trying this it most have had too much coolant in it already and it would start to overflow when I would idle it up. Hopefully I didn't mess anything up by doing this?
 
#15 ·
I also just completed full EGR delete on my 2011 LML about 5 weeks ago.
For the first week, everyday and any time the truck was driven I made sure the tank was filled to the top, then with the cap on vigorously squeezed the upper hose a few times. While squeezing that hose sometimes I could see or feel a burp in the tank. I did this before starting it up and then again before shutting the engine off. The hose did not feel full and the tank was lower the first 6 or 8 times I did this. Even after the hose felt full I followed this procedure a few more days. With a little over 300 miles on her there has been no sign of over heating or coolant loss.
Through my research and talking with others this is the first time I have heard of the vacuum plan.
 

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#17 ·
I can squeeze the hose when it's cold but once I've drive it and it's hot the hose is rock hard. Does that mean it is full of coolant or is that just gas/air? I'll try squeezing it a few times before starting it, but I would have to let it cool down a little before I could squeeze after I run it.
 
#16 ·
Yea I followed the procedure EXACTLY when I refilled it the first time. Now after I ran it and after it cooled off the level dropped to about the seam and this time I just poured some more coolant in it to top it off I did not go through the refill procedure again't, but I figured that was ok. But then after I realized it was filling up the overflow I pretty much did all the differant things everyone suggested, I jacked the front end up and let it idle for about 20 min and I got it hot and cracked open the cap to release the built up air/pressure. And today I replaces the cap with a new one. And still the same problem, passenger side filling up until it overflows and the engine/driver side of the tank empty. And the truck had still not once overheated or even went above 210 degrees. I'm at a loss with it. I don't know what the hell is going on. I'm really starting to think maybe I should have listened to the mechanic and had it vacuumed.
 
#22 ·
Yea I followed the procedure EXACTLY when I refilled it the first time. Now after I ran it and after it cooled off the level dropped to about the seam and this time I just poured some more coolant in it to top it off I did not go through the refill procedure again't, but I figured that was ok. But then after I realized it was filling up the overflow I pretty much did all the differant things everyone suggested, I jacked the front end up and let it idle for about 20 min and I got it hot and cracked open the cap to release the built up air/pressure. And today I replaces the cap with a new one. And still the same problem, passenger side filling up until it overflows and the engine/driver side of the tank empty. And the truck had still not once overheated or even went above 210 degrees. I'm at a loss with it. I don't know what the hell is going on. I'm really starting to think maybe I should have listened to the mechanic and had it vacuumed.
If you are following the refill procedure exactly, then when you are re-warming from cold it should be with the cap OFF, and you would not be cracking it when warm to release pressure
 
#18 ·
I forgot to mention that the heater was ran the first few times it was driven also.
I wish you a swift and successful fix to your problems!
 
#20 ·
And now I have discovered a new problem. I'm hearing a squealing noise when I push on the gas. At first thought it was normal because I was told I might hear a louder whistle after replacing the stock up pipe but now it's getting a little louder so I'm thinking maybe I have an exhaustive leak. This truck has been much harder to work on than any of my previous gas trucks. I'm almost at the point of just bringing it to a mechanic as much as I hate to let it defeat me like that lol.
 
#27 ·
Yes it was. This is why I deleted the EGR cause I thought that was the the problem. Before it was just slowly using coolant, it would go from the min Mark to the seam maybe every 5 days. Now it's just building up pressure until it spits it out. Not sure why it all of sudden changed like that after the egr delete. I also replaced the up pipe so maybe with the added HP, better airflow, it's now causing more pressure.
 
#30 ·
When you say this, do you mean upgrading the cp4 to a cp3?? And why do you have to do this? Is this better than just installing a lift pump? Or do you still have to install a lift pump even with the cp3? Sorry haven't done much research on the fuel system yet, been trying to get past my coolant problem first.
 
#33 · (Edited)
I'd run a lift pump with either a cp3 or cp4 extra filtration and steady fuel supply will take stress off the system in higher tunes...the h&s brings up a different set of obstacles.

If you want to keep the h&s you will need to get mcc tunes from ppei (kory Willis) in order for the truck to operate properly with the cp3 (the pumps flow differently).
I would sell the h&s (powerstroke and cummins guys will snatch it up). And get EFI live from one of the reputable tuners.

After a cp3 you'd have a pretty dang reliable truck.

Sent from my iPhone using Tapatalk
 
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