[Cobra20646]

In most everyday cars, the radiator filler neck is the highest part of the colling system, and air will naturally seek this place to escape and allow a full load of collant to be poured in.

Our little cars usually have the radiator below the the engine coolant outlet, so using the radiator filler neck to fill the system is not going to let you burp all the air out. On some cars, the expansion tank is located above the engine and filling the engine with coolant is easy. Without the expansion tank, the use of an "in-line" filler neck placed in the upper radiator hose at the highest point will allow the air to rise and escape, and allow a full load of coolant to be poured in.

The hole drilled in the thermostat flange will let the air bypass the thermostat valve until the coolant reaches the temperature to open the thing.

Air bubbles will rise to the top of the highest place in the cooling system, so make sure this is the place you install the filler neck, or you'll never get all the air out.

I'm sure there will be others who will disagree, but this has worked for me time .... everytime.

- Jim -