# air in radiator



## geosmax (Feb 6, 2009)

I have a 2002 max gle. I tried to "burp" trapped air from my radiator and here's what happened. Took the rad cap of, turned the heat on and ran the car until the cooling fans came on, coolant got sucked down into the radiator. 

Then i turned the heat off. The coolant did not go anywhere in fact it started to spill out of the radiator. The only time it went down is when I had the heat on in the car. Is this normal? Even with the heat off, shouldn't the thermostat still open and allow coolant to flow thus the level in the radiator should go down and not spill out?


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## rogoman (Dec 16, 2004)

Once the motor is fully warmed up, the thermostat should be fully open. You may have a faulty thermostat. Before condemning the thermostat, do a system air purge first.

Here's how I do it:
1 - drain coolant
2 - open the bleeder screw
3 - optionally jacking up front of car helps to purge air pockets
4 - fill system until coolant starts coming out the bleeder hole
5 - close bleeder screw (not too tight; screw is easy to break off)
6 - continue filling until coolant is at the bottom of the filler neck
7 - do not put cap on the radiator
8 - start motor; as coolant starts to warm up, you may see a few air bubbles
9 - squeeze the hoses by hand to free up possible air pockets
10 - put cap on radiator


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