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Discussion Starter #1
I will be flushing out the engine coolant next month and I want to make sure this is the proper way.

I usually take the garden hose and run as much water constantly down the radiator while the engine is running with the drain plug removed.

I have done this way twice on another vehicle and I want to make sure I will not damage anything on the Commander.

I am surprised no one on the forum has talked about a coolant flush. I know we have the better (HOAT) coolant which is good for 5 years or 100,000 miles, but changing the coolant early does not hurt.

I will try and create another How to thread with better pictures :).
 

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Buy some Prestone Super Radiator Flush and follow the directions on the bottle.

 

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I have been thinking of doing a coolant flush/refill but wondering is the dealer the only source for the HOAT coolant?
 

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No, you can get it at a regular auto store, but be sure that it meets Chrysler's standards. My advice, buy it from the dealer: its about the same price, you'll know its the right stuff, and you can usually get a discount just by asking.
 

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No, you can get it at a regular auto store, but be sure that it meets Chrysler's standards. My advice, buy it from the dealer: its about the same price, you'll know its the right stuff, and you can usually get a discount just by asking.
Thank you for the quick answer so a visit to my local dealer will be on my list. I was wondering how similar/different HOAT is to Dexcool but not worth the worry to find out.
 

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Discussion Starter #6
Dexcool cannot be used in our vehicle.

I believe there are only 2 HOAT coolant available. One is the coolant from the dealer and the other is called Zerex G-05.

Jeep5253: The coolant should not have too much deposits so I will only be using water.
 

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Dexcool cannot be used in our vehicle.

I believe there are only 2 HOAT coolant available. One is the coolant from the dealer and the other is called Zerex G-05.
You are absolutely correct!
 

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Discussion Starter #8
According to the instructions for Prestone Super Flush, they say to fill the radiator with the solution and then tighten the radiator cap. Then turn the engine on and let it run for......

I really want to have a good stream of water flowing to remove any small deposits that might have build up over 4 years.

I guess what I am asking is it OK to keep the engine running while fresh water is following through the radiator? I am not sure if any air pockets will be going through the water pump during this process.
 

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If I were to do mine I would drain the radiator, refill, then run engine. How are you going to keep the system from getting too diluted during your running-flush? And where is all the fluid running off to? Are you just trying to purge the radiator, or more of the system?
 

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The draincock will be open so all of the water will drop into the 15 qt. pan.

I am glad we have a bleed screw which will help eliminate the air when it is time to refill the system.
 

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I guess what I am asking is it OK to keep the engine running while fresh water is following through the radiator? I am not sure if any air pockets will be going through the water pump during this process.
I have never heard of anyone but you using this method, and I certainly wouldn't do it on my vehicle.
 

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Why don't you just spend a few bucks and use the flush solution ? It is made to disolve and get rid of those deposits and you won't have to sit there and keep your eye on the temp gauge and keep a hose running.
 

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Another issue with just running water through the radiator is just that, you want the water to flow through the motor and you will not get effective cleaning if this is not done under preasure which it would not be it the cap is off and the drain open.
 

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another issue with just running water through the radiator is just that, you want the water to flow through the motor and you will not get effective cleaning if this is not done under preasure which it would not be it the cap is off and the drain open.
x2
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Discussion Starter #16
I figured it worked fine on the other vehicle so why not do the same procedure on the Jeep.

Well I will see how it turns out after I make a trip to the dealer to get the coolant.
 

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when i drain and fill my vehicles i add redline water wetter. it supposedly allows better heat dispersion
 

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Discussion Starter #18
Did anyone have any problems when removing the bleed screw? I was not able to remove the screw since I was starting to round off the edges. I even used a 3 foot cheater bar, but I did not want to mess up the screw. Due to this, I had plenty of air in the system and it took a while to get all of the air out.

For those who are thinking of draining their coolant, make sure you can remove the bleed screw or you would spend most of your time removing the air in the system.
 

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So did you remove the thermostat like they did in the video you linked to?
The little 2.0 G.M. engine in the vid uses a drop in thermostat.
By having it out, one can be assured there is full flow from block to radiator while flushing.
This thermostat removal on conventional cooling systems (ours) would not be quite as simple and disassembly/reassembly would have to occur twice.
Simply put, not the way it is done.

There are several schools of thought regarding coolant service.
I am not a fan of flushing a system unless you are trying to undo poor maintenence of a previous owner and are dealing with a goodly amount of corrosion and rusty coolant.
However, as this is written, for the most part the 06 MY's are coming up due for coolant service (5 yr) and, truth be known, none of them should require a flushing proceedure.

So, my recommendation is quite simple.....just perform a drain and fill with new coolant.
You are restoring about 95% of the anti-corrosives and, if you do your 50/50 mix prior to pouring it into the cooling system you don't even have to consider worrying about 'if I have enouph' coolant to water ratio.
Since we are discussing coolant maintainence and not undoing poor service there is no need to introduce cleaning acids or fresh water flushing proceedures with the potental of causing cooling system damage during the proceedure.
That damage could be from acid attack on the inside of the heater core or the backside of the freeze plugs or even the somewhat fragile water passage areas of the head gaskets.

So, IMO, Get a couple of gallons of the correct coolant and premix with demineralized water (You know....the stuff they sell at the grocery store).
Use a SIX (6) Pointed socket or wrench to crack the bleeder loose (not to be removed yet, your loosening it for later convenience).
Remove the radiator cap (to allow easy draining) open the drain and catch the old in a suitable pan.
While it is draining, remove the overflow tank and pour its contents into the pan as well.
Flush the tank out with fresh water and rinse the radiator cap....if the gasket area shows any cracks, replace it.
Now, re-install the now clean and empty overflow.
Once the radiator has finished draining (don't wait for it to stop dripping.....it'll do that for the next 6 hours or so) Close the drain.

I probably should have put this to the front but you really should have 3 or 4 one gallon empty jugs.
1 to make up your 50/50 pre-mix and the others to pour and measure what you have drained out.
You need to know about how much your hoping to put back in the system, right?
Anyways, now that you know what came out, it's time to refill.
Now you can remove the bleeder screw.....keep it handy, like in your pocket if you loose things alot.
Take your time refilling, the coolant has to work its way through the entire block and all those little tubes in the radiator.
And, if you pour too fast, it just upchucks out of the fill hole.
You will reach a point where coolant begins to come out of the bleeder hole....re-install the bleeder plug.....dont overtighten, this is a pipe plug thread and the threaded area grows larger as the the plug is tightened.....too tight and the plug will split the housing.
You can use a bit of teflon sealer on the plug but they generally seal fine without it.
Continue to add coolant till it stabilizes about one inch below the radiator cap area.

Now, with the cap off, start the engine and turn the HVAC controls to floor heat and temp control to full hot......leave the fan speed at its first blow position.

Watch the coolant level and occasionally feel the upper hose....you likely will add a bit of coolant to maintain that one inch level.
You will feel the thermostat open.....the upper hose will get hot, fast and at that point you likely will see the coolant level drop, so add a bit more, again trying to hold that one inch depth.

Reach into the vehicle and see if you are getting hot air from the outlets.
If you are, top off the coolant, close the cap and shut it off.

If you are not getting hot air, install the cap ONE click and then hop in the vehicle and hold the rpm at 1500 while feeling outlet temp.
In a minute or so you should feel heat.....if not, nail the throttle a couple of times....this will evacuate the air from the heater core.
Then, shut it off.
In about five minutes, remove the half latched cap and top off the coolant.
Now fully reinstall the cap.

Refill the overflow to the full HOT line.

Now compare what you took out with what you put in.
Most of the time, you have removed more than you put in.
If you are about a quart in difference, you can assume there is air in there and it will be pulling that out of the overflow jug over the next few days.

Go for a drive, maybe 15/20 minutes and park it.
In a few hours, remove the cap and see if it needs a top off and do so if required.
At very least, you may find you need to adjust the level in the overflow jug over the next few days.

A lot of writing for a simple job.....maybe you all will find it useful.

Rob
 
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