how do i bleed the cooling system+antifreeze question

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hadtomer

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Hello to all.

Im currently in the process of servicing my liberty (V6)- iv'e had it for one week - and i like a fresh start with new coolant and oil (you call in antifreeze in the states).

1. I have a load of PRESTONE coolant right here at home. left over from my old SUV. yellow(ish) container. no adding water or nothing. pre mixed. but i can go to a nearby chrysler dealer and get some mopar coolant. which is better?

2. If i go for the MOPAR coolant- should i mix it with water? (not tap water of course).

3.I have read lots of reviews and how to guides about replacing the coolant. no problem there. however- some say that if you let the engine run 1 hour the system will bleed the air out. others say you need to bleed air from the allen bolt on top of the engine. which is correct?

4. If i have to bleed the system with the allen bolt - should i do it when the engine is cold? or do i get it to working temp and wait for the thermostat to open?

Thanx!
 
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Tog

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Just make sure whatever you use is HOAT coolant

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jja

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Do NOT open any part of the system when hot!

You can use the allen bolt and this will get some air out but not all of it. If you have 06 or 07 truck all the air left in the system will end up at the top of the radiator after some driving. However, it won't make its way to the depressurized overflow tank under the hood and neither would the coolant from the overflow tank make it to the rad. So in effect you'll see correct coolant level on the overflow tank but your rad is gonna be somewhat empty. So after some driving wait for the engine to cool off completely and then open the rad cap. Pour coolant till it overflows. Repeat until you start finding the thing full.
 

teeje

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Do NOT open any part of the system when hot!

You can use the allen bolt and this will get some air out but not all of it. If you have 06 or 07 truck all the air left in the system will end up at the top of the radiator after some driving. However, it won't make its way to the depressurized overflow tank under the hood and neither would the coolant from the overflow tank make it to the rad. So in effect you'll see correct coolant level on the overflow tank but your rad is gonna be somewhat empty. So after some driving wait for the engine to cool off completely and then open the rad cap. Pour coolant till it overflows. Repeat until you start finding the thing full.
Haven't had any issues with prestone 50/50 mix. HOWEVER I have a new engine, heater core, radiator and all new hoses..soo..that being said...whatever is in there, stick with it

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dude1116

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Hello to all.

Im currently in the process of servicing my liberty (V6)- iv'e had it for one week - and i like a fresh start with new coolant and oil (you call in antifreeze in the states).

1. I have a load of PRESTONE coolant right here at home. left over from my old SUV. yellow(ish) container. no adding water or nothing. pre mixed. but i can go to a nearby chrysler dealer and get some mopar coolant. which is better?

2. If i go for the MOPAR coolant- should i mix it with water? (not tap water of course).

3.I have read lots of reviews and how to guides about replacing the coolant. no problem there. however- some say that if you let the engine run 1 hour the system will bleed the air out. others say you need to bleed air from the allen bolt on top of the engine. which is correct?

4. If i have to bleed the system with the allen bolt - should i do it when the engine is cold? or do i get it to working temp and wait for the thermostat to open?

Thanx!

Do NOT open any part of the system when hot!

You can use the allen bolt and this will get some air out but not all of it. If you have 06 or 07 truck all the air left in the system will end up at the top of the radiator after some driving. However, it won't make its way to the depressurized overflow tank under the hood and neither would the coolant from the overflow tank make it to the rad. So in effect you'll see correct coolant level on the overflow tank but your rad is gonna be somewhat empty. So after some driving wait for the engine to cool off completely and then open the rad cap. Pour coolant till it overflows. Repeat until you start finding the thing full.

Please don't bleed the system like this. You'll end up with too much coolant. It's always worked out that if I loosten the allen head a little, and run with the rad cap off (HEAT ON!!!) I tend to bleed all of the air out fairly quickly. I've had to replace the coolant in this twice already.

Haven't had any issues with prestone 50/50 mix. HOWEVER I have a new engine, heater core, radiator and all new hoses..soo..that being said...whatever is in there, stick with it

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Please for the love of god do NOT use Prestone unless you want premature failure of coolant system parts. Mopar HOAT coolant or Zerex G01 HOAT only.

Hope this helps...
 

teeje

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Please don't bleed the system like this. You'll end up with too much coolant. It's always worked out that if I loosten the allen head a little, and run with the rad cap off (HEAT ON!!!) I tend to bleed all of the air out fairly quickly. I've had to replace the coolant in this twice already.



Please for the love of god do NOT use Prestone unless you want premature failure of coolant system parts. Mopar HOAT coolant or Zerex G01 HOAT only.

Hope this helps...
Well, the company I paid to install the engine put it in and I have a 100,000 mile warranty so it's on them

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eradicator006

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The yellow jug prestone doesn't meet the MS 9769 standard which the jeep requires. The silver jug prestone (says dex-cool approved) does meet MS 9769. I would think as long as the coolant meets MS 9769 then you're good to go.
 

dude1116

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The yellow jug prestone doesn't meet the MS 9769 standard which the jeep requires. The silver jug prestone (says dex-cool approved) does meet MS 9769. I would think as long as the coolant meets MS 9769 then you're good to go.

HOAT only. It's phosphate free. And it's got much better anti-corrosion properties than regular OAT or IAT coolant. I would suggest if you don't want heater core, tstat, or water pump issues in the future that you use the correct coolant.

Mixing any of the types of coolants will cause sludge.
 

tommudd

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Well, the company I paid to install the engine put it in and I have a 100,000 mile warranty so it's on them

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Will they cover heater core, radiator etc as well ?
I highly doubt they would will be interesting
 

teeje

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Will they cover heater core, radiator etc as well ?
I highly doubt they would will be interesting
Those, yeah I already replaced [emoji14]

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jja

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Please don't bleed the system like this. You'll end up with too much coolant. It's always worked out that if I loosten the allen head a little, and run with the rad cap off (HEAT ON!!!) I tend to bleed all of the air out fairly quickly. I've had to replace the coolant in this twice already.

You can't really end up with too much coolant. The system has to be completely full and that's it. There is no space for more coolant.

On a 06 and 07 the overflow tank is depressurized and there is a valve in the radiator cap that when open would let some coolant flow to/from the tank. This valve opens if pressure is high enough. If you have a lot of air at the top of your rad the valve never opens. So you have half empty rad and full overflow tank. It's kinda dangerous to drive like this.
 

dude1116

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You can't really end up with too much coolant. The system has to be completely full and that's it. There is no space for more coolant.

On a 06 and 07 the overflow tank is depressurized and there is a valve in the radiator cap that when open would let some coolant flow to/from the tank. This valve opens if pressure is high enough. If you have a lot of air at the top of your rad the valve never opens. So you have half empty rad and full overflow tank. It's kinda dangerous to drive like this.

You can most definitely overflow to one of the return lines on the coolant overflow bottle. Will it hurt? Probably not but why take the risk when you can just bleed the system correctly?
 

blackhawk

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The easy way I have found to replace the old HOAT is to disconect the lower rad hose and fill in thru the upper rad hose.
Afterwards, you must start the motor and complete. Maybe you need to add after a little ride.
I have done this about 4 times to both Libby and not issues so far.
 

jja

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You can most definitely overflow to one of the return lines on the coolant overflow bottle. Will it hurt? Probably not but why take the risk when you can just bleed the system correctly?

On 06 and 07 there is a single line connecting the overflow bottle to the rad top right where the cap is. You can't overfill this line since it has to be full anyways and it's going higher than the cap. That's exactly the reason you can have empty rad and full overflow bottle on these.
 
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