Removing air from cooling system -- does this work?

[Jesda]

"Fill the radiator and reservoir and start the engine. As the engine runs, coolant will begin to circulate and the level will fluctuate. Continue adding coolant to keep the radiator near full until the engine reaches operating temperature. Rather than fill it right to the top, leave a little space in the filler neck. Air, trapped inside the system, will work its way out and can splash the now-hot coolant out. Turn the car's interior heater on. Shortly after the engine reaches operating temperature, the thermostat will open. When this happens, you'll notice a sudden drop in the level of coolant in the radiator as the system takes new coolant in. This may happen a number of times, until the system is completely full and free of air pockets. It is sometimes difficult to remove all the air trapped in a system; it simply takes time. Take care, as the engine will now be very hot and can cause serious burns."

[elwesso]

I tried when I did the coolant flush to run the car with the cap off and trust me it doesnt work.....

Your best bet is to just to fill the res a lot and go from there...

[gniknave]

I've bled my 240's cooling system a few times in the past day for various reasons. NISTECH told me a nice procedure to do it. I'm sure the procedure is similar, but here's what he said.

Drain the radiator with the cap removed.

Replace the drain plug & fill the radiator.

Once the radiator is full, fill the reserve to "Max"

Put a bleeder funnel in the radiator filler neck and fill it half way (level shouldn't go down)

Start the car and turn on the heater full blast

Let the car warm to normal operating temperature

Once it is in that area goose the throttle, let it come back and stabilize at idle, then goose it again, and let it idle for a couple minutes. Do this for about 10 - 15 minutes after it reaches operating temperature. (may be shorter time on the Q)

The key is to let it settle at idle between each goose. Without the radiator cap on the system can't really build up pressure, so the goosing of the throttle from idle gives it a bit of pressure by speeding upthe pump sharply. When goosing the throttle, you are snapping it to around 4 - 5k rpm and letting go. Don't hold it there.

When I did this I noticed that after 5 minutes I saw large air bubbles come from the funnel and then it tapered down. Eventually I saw no bubbles at all.

When all the air seems to be out then shut off the car, replace the radiator cap, and top the reserve to max again if it is low.

He also recommended it being on a slight incline (I had it on ramps) when doing this procedure.

[FarFetched]

Do you still have your old radiator caps?If you do, cut off the valve itself with spring leaving only the cap and the rubber gasket. Fill the system, screw rad caps on (use both) and run it (drive it if you want- preferably) In alomost all cases this trick purges all the air from any system. Just watch your expansion tank, not to get it empty!Cheers!