Getting trapped air out of cooling / heater system

Hello,

Does anyone here have any suggestions as to how to go about getting trapped air out of the cooling / heating system? Both the front and rear heaters used to work fine, but recently the rear heater stopped getting hot and I can hear gurgling up front in the system. I suspect that it's air trapped in there that's causing the problem. Do I need to drive up some steep hill and open up the radiator cap to let the air gravitate to the top?

Someone mentioned opening up the radiator cap after parking the vehicle (engine hot, thermostat open) for the night. Is that the correct way to do it?

Thanks in advance to those who post a reply here.

Peter.

Reply to
Peter Bogiatzidis
Loading thread data ...

How long has it been since cooling system has been serviced? If it's been a while then you should do that as well as look for any problems. If your radiator cap is old you should replace it. It's a dual action cap - lets fluid flow both ways - to prevent air being in cooling system. Gaskets on cap can go bad and allow air to get in. After cooldown check radiator to see if full and overflow to see if up to correct mark. If not then you are losing coolant and need to find out where. Check hose from radiator to overflow tank to see if cracked, broken or pulled off radiator connection. Also check your overflow tank to see if it's up to correct fill mark. Check all cooling and heater hoses at ends to see if any seepage or leakage there. If they are seeping under pressure then they can lose coolant and let air in system on cooldown. Some vehicles require parking uphill - front higher than rear - and letting vehicle cool down. You may have to bring to warm temperature with radiator cap off then shut off and let cool down. Monitor radiator fill port closely as coolant can explode out if you let it get too hot with cap off. Usually as soon as you start getting temp in coolant you will see it rise in filler and it's time to shut it off. HTH, davidj92

Reply to
davidj92

You don't give the age of the vehicle. The heater core might be clogged with sediment either from rust from the engine or precipitates formed from the antifreeze and certain minerals in some tap water.

A strong reverse flush might help. I've never had air in the system except when refilling after a flush & drain.

Ken

Peter Bogiatzidis wrote:

Reply to
Ken Shelton

MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.