Getting the air out of the cooling system???

How do you get all the air out of the cooling system??

Seems no matter how hard I try, the upper hose always has air in it. I think this is causing my system to overheat from time to time.

Going to do some wheeling near Mojave and don't want to overheat this weekend!!!

Any ideas??

Thanks,
Paul

I use one of the Prestone flush-Tee gizmachies....it comes in a flush kit from Prestone. Most auto parts stores carry them. Works pretty well in upper hose location to burp all the air out.

I do replace the "tee" once a year because the plastic does get brittle. You can buy the individually for about $3 without having to buy the whole flush kit, at most well stock parts stores.

Since they'r pretty cheap, I keep an extra one in my glovebox just in case....

first, what year.
If it is an HO, they are supposed to "burp" themselves.
If it is a Renix, you have to jack the rear end up and let it run for a while, so all the air gathers in the rear top of the head. Then let it cool and remove the temp sender (while off) and fill from the hole and replace the sender. It is also possible to do this or loosen a heater hose while it is running, so the air escapes---but if you are not very careful you will get burnt.

Remember, the air will be trapped either in the top of the head or in the heater core since they are the highest points of the system.

Paul R said:

How do you get all the air out of the cooling system??

Seems no matter how hard I try, the upper hose always has air in it. I think this is causing my system to overheat from time to time.

Going to do some wheeling near Mojave and don't want to overheat this weekend!!!

Any ideas??

Thanks,
Paul

Click to expand...

If you have a HO 4.0 with the open cooling system, the system is self-burping. Since yours isn't burping itself, the chances are that the radiator cap is bad. This allows the coolant to boil inside the engine and form steam pockets.
If you have a Renix 4.0, replace the pressure cap on the expansion bottle and make sure the bottle itself isn't cracked.

It's an 89 4.0. I have a new cap on it. The upper hose never seems ot have any water in it, or VERY low flow and I think this is because of the air in the system.

Is it worth it to change it over to a different system??

Thanks,
Paul