When you flush or replace the coolant or antifreeze in your Neon you will need to bleed the radiator to get rid of any air that is trapped inside. Bleeding is typically done after the radiator has been drained of the old coolant and has had new coolant added. Bleed the radiator on your Neon after you have purchased the coolant or antifreeze for the radiator at an auto supply store.
Place a drain pan on a large plastic tray under the radiator. Locate the drain valve that is on the passenger side of the radiator.
Open the drain valve to let the coolant flow into the drain pan or plastic tray. Unscrew the radiator cap to allow the coolant to drain out faster.
Wait about an hour for all of the coolant to drain from the radiator. Close the drain valve and replace the radiator cap.
Unscrew and remove the cap to the coolant reservoir. Insert a funnel into the coolant reservoir.
Pour a 50/50 mixture of water and antifreeze into the funnel until the level reaches the fill or "max" line on the side of the reservoir.
Start the engine to allow the coolant to pump through the radiator. This will allow air pockets to "burp" out of the system. Turn the engine off and repeat step 2.
Turn on the engine again and let it run to bleed the remaining air out of the system. Turn off the engine and replace the radiator cap to complete the project.
