""I question if your using the correct style tank, per my link above. That style tank must be mounted above the radiator and is designed to be used as fill for a radiator. That style won't work correctly down low with our radiators that are designed to be filled through the radiator cap.""

I used the Dorman 603-121 which is called a "Pressurized Coolant Reservoir". The tank is mounted lower than the top of the radiator and the fluid moves back and forth with no problems.

After my last drive, the coolant reservoir once again went dry. This is the fourth time that I have added coolant to the reservoir and the radiator sucked it in. I must have had a decent size air bubble in the system.

Thanks for the replies. I am going to keep adding coolant to the reservoir until the level stays within the height of the reservoir after a full driving and cool down cycle.