Hi all,

Quick question, how much of the coolant can be drained using only the radiator drain? I know the total cooling system capacity is 11.7 qts.

 

I remember my story that comes with radiator petcock valves. They quite often gets clogged, stuck or leaking if You manage to open them somehow. So in vast cases people used to pull off the bottom radiator hose to drain. The amount drained that way doesn't have much in common with a radiator's volume.

I've replaced my radiator and still keep the old one. I can measure the volume if no answers

 

For easy math, I'll just say the system holds 12 quarts.

I believe you can get 4-5 out by removing the lower radiator hose and letting air into the system by unbolting the thermostat housing.