2010 Coolant Replacement Questions...

[KOwens]

OK TDR Gurus,

Time for the first coolant change on my 2010 CTD. I haven't reached 75k miles yet, but have reached the 60 month interval. Anyway, I've read and re-read the instructions on the CD-based service manual I have from Tech Authority and have a few questions for those of you who have already performed this routine task.

My first question has to do with draining the coolant. Is it necessary or recommended to remove the air vent (air bleed) plug near the EGR cooler during the draining process...or is it best to leave it in place until refilling with coolant as stated in the instructions? The reason I ask...is because I'm wondering if a more complete engine drain (not just from the radiator) would be achieved if air was allowed to flow into the engine block from this air bleed vent opening. Anyway, your thoughts on this operation would be appreciated.

My next question has to do with cleaning or flushing the system. When is it appropriate to clean the system...either with clean water or a flush...as described in the CD-based manual? I'm guessing for my first coolant change, it should be fairly clean inside, and no additional cleaning by water circulation at operating temperature or the use of flush would be required...and that simply replacing the coolant with new would be sufficient. Any comments on this phase of the show would be appreciated also.

Finally, a coolant filling question. During the filling phase...with the air vent (air bleed) plug removed near the EGR cooler...does the air from the engine block escape rapidly and completely during the initial fill, or does it take some time for it to percolate out of the engine during a few operation cycles? Again, reason I ask is because the radiator filler neck is roughly an inch-and-a-half higher than the top of the air vent (air bleed) tube...so going back later once the radiator is completely filled and removing the air vent (air bleed) plug will cause coolant to escape...rapidly I'd think...out of this hole. I'm guessing any re-check for air from this vent must be done carefully...perhaps cracking it loose long enough to see some air bubbles come out followed by air-free coolant...then quickly tightening the plug back down before topping off the radiator. For those of you who have performed this maintenance, how many times (hot/cold operation cycles) do you continue to check for trapped air from this air vent (air bleed) plug before assuming your got it all out of the engine?

Anyway, if you made it this far through my long-winded thread...thanks for reading...and if you can provide any insight before I take the plunge, I really appreciate the help.

Thanks, Kevin

 

[JohnCW]

I have just serviced my 2011 today with Zerex-G05. I only removed the vent plug ( tighter than all get out ) when filling the radiator and reinstalled as the fluid was gushing out.
I did not do a flush , only drained the radiator and siphoned out the overflow tank. I measured the old fluid and was able to replace the same amount.
Took it on a test drive to reach temp, it is now cooling down and this evening I will crack the EGR vent to see if any air is present.
One thing I noticed was the Zerex is very pale yellow and looks like water in the overflow tank, not very exciting looking stuff !

 

[JohnCW]

Update, after cool down I removed the vent plug slowly ( nothing happened ) then cracked the radiator cap and one small air burp ( just like an old coffee peculator )then fluid flowed out , so quickly closed radiator cap and reinstalled vent plug.
The radiator was full and the overflow tank was at proper level. I feel like all is well under the hood.
Hope this helps.

 

[KOwens]

Hey JohnCW,

Thanks for the info. I was thinking (since the vent opening is below the radiator cap fill level) that it would gush once opened after fill. Good to know you can see, hear, or otherwise tell some air escaped before clean coolant began flowing out the vent opening...I was hoping that would be the case. Wonder if you should check it again later after a few (hot/cold) cycles...to be sure no other air is currently trapped in the system. Any plans along those lines? Just wondering.

Also, I plan to use the Mopar original recipe coolant...so I guess the color change issue you are dealing with should not be an issue...assuming Mopar doesn't change the color on me! Wouldn't it be nice if everyone would just settle on a standard color and stick to it. HOAT coolant is HOAT coolant, right? Why change the color?

Again, thank you for weighing in...appreciate your experience and description of what you did to get 'er done!

Kevin

 

[JohnCW]

I have a little 400 mile round trip this Saturday so that will purge any demon air pockets out of the 6.7. In hindsight I would have paid for the Mopar just to have some color , perhaps I should add some red dye.
Good luck on the HOAT job.
John

 

[KOwens]

That could work! Have a safe trip.

Kevin

 

[Loren]

... For those of you who have performed this maintenance, how many times (hot/cold operation cycles) do you continue to check for trapped air from this air vent (air bleed) plug before assuming your got it all out of the engine?

Thanks, Kevin

Kevin,

I fill my system as full as I can using the procedures discussed here. The way I know that the system has no more air in it is by monitoring the overflow tank.

Every time the engine heats up the coolant expands. If the system has air in it the air will be forced into the overflow tank. When the engine cools, coolant from the tank will be drawn back into the radiator and the overflow tank level will decrease. This will continue for every heat-cool cycle until the system has no more air. At that point the system will force coolant into the overflow tank when it heats up and suck coolant back into the radiator when it cools, resulting in no change to the level of the overflow tank.

When the overflow tank level stops decreasing from day to day, the system is full. For me this is usually half a dozen cycles, more or less.

Good luck with your maintenance.
-- Loren

 

[AnOldBiker]

Something I noticed on my first coolant change was the angle of the engine block. The back sits lower than the front. I have some old ramps that are sort of tall, and back the truck up on them. Then I start draining the system. I found I dropped more liquid doing it this way than the first time I did it. My engine is a bit different than yours, but I roll the truck off the ramps and pull the thermostat. When it is button up, minus the thermostat, I fill up through the thermostat opening until it is filled, then replace the thermostat and finish the fill. With the puck bottle filled, I fire the truck up to temp. Very little fluid is needed to cap off.

Just thought I mention about the lower side of the engine block might hold more than you think.

 

[Wayne M.]

Just a few thoughts to add that I didn't catch.
On the drain down using the radiator petcock, leave the system sealed up. This will cause the expansion tank to drain just as if the engine were cooling. After the tank is down, then you can open the cap and whatever bleeds there are.

The Ph of the system is extremely important. As long as there is no contamination, and the coolant is not 10 years old, best to just do a drain and refill with the right stuff. I've been using GO5 premixed with good results.

Fill with the bleeds open, and once everything is topped and run a couple of heat cycles, you'll see the expansion tank settle. After you make that up it should be good for another 5 years or your EGR service or your water pump goes.