2006 Jeep Liberty cooling system help

[AndyB]

Need a little cooling system help. This is the son’s 2006 Jeep Liberty with 194,000 miles on it.
We have been bringing back up to specs for the last year. Last problem is the cooling system. It has occasionally burped coolant out of the overflow tank. By occasionally I mean no specific time interval or temperature. Just really random.
The overflow tank on it now doesn’t have any pressure control means. The cover is just a snap cap like on a windshield fluid reservoir. The reservoir has 2 1/4” tubes, 1tube vents to the atmosphere, the other goes to radiator.
Not seeing how this could pressurize the cooling system, I checked out the coolant tank and ordered a new one with a pressure cap and 3 lines. The new tank has an additional 5/8 line fitting on the bottom.
Where does this 5/8 hose hook up to the engine? Can’t find a picture anywhere.
Cooling system was just serviced last weekend and it has never overheated while we’ve owned it.
Thanks,
Andy

 

[atikovi]

Gas or diesel?

 

[CarDoc66]

Most all the 3.7 KJ Liberties had a pressurized coolant bottle mounted on the firewall. Assuming yours is a 3.7 I wonder how it ended up with an standard overflow.
If I recall correctly, one of the heater hoses had a tee which branched off the metal pipes (along the firewall) to that bottle.
Is yours gas or diesel?

 

[AndyB]

Sorry, it’s the 3.7 V6 gas.

 

[CarDoc66]

Sorry, it’s the 3.7 V6 gas.

There should be metal heater lines along the firewall where the coolant bottle tee’s in to one of them.

 

[AndyB]

Thinking I should just go buy the 5/8 hose that connects to the overflow tank and see where that puts on the motor. It’s a molded hose.

 

[mattd]

Is there a pressurized cap somewhere on the radiator or upper hose? If so, that bottle you purchased is wrong. IIRC most liberties that I have worked on just have a recovery tank like you stated you have.

 

[AndyB]

No other pressure cap. Radiator only has upper and lower hose connections and 1/4 hose connection for hose from overflow tank. Can’t figure out how cooling system could pressurize with current set up.

 

[CarDoc66]

No other pressure cap. Radiator only has upper and lower hose connections and 1/4 hose connection for hose from overflow tank. Can’t figure out how cooling system could pressurize with current set up.

Your heater lines are suppose to tee off to the pressure bottle. If it doesn’t you have the wrong heater lines in the truck.

 

[AndyB]

Thinking you are correct. Thanks for your help! Something new to research.

 

[CarDoc66]

Thinking you are correct. Thanks for your help! Something new to research.

Rock Auto sells the entire bundle, all the pipes, hoses and clamps for short money (from Doorman).

 

[zrxkawboy]

We have an '06 Libby. I'll go out to the garage later and take a look.

 

[HemiBenny]

The early Liberty’s 2002-2007 had the pressurized “reservoir” if you will. (Like you have pictured)
The 2008 and newer just had the plain old reservoir with the snap cap like the washer fluid reservoir on it. In fact the coolant reservoir and washer fluid reservoir on the 2008 and newer was one big unit together. The radiator on the 2008 and up had a pressure cap on it.

 

[zrxkawboy]

There is a hose that curves down, back, to the driver’s side, and forward to a metal pipe. I am pointing to both ends of this hose.

 

[2EHA]

with a low psi cap you can hook it up to a bottle and it will get sucked back into the expansion tank after it cools down.