type of radiator coolant goes on a 1999 expedition

What is your question?

leaking coolant and maybe water. ( Does not over heat. The less in reserve tank the less the leak. Use 50/50. Short of coolant so I added water. Seems to hold water longer and does not over heat when I went round trip of 280 miles. No noises, runs smooth.

What makes this problem better or worse?

If I put just water for the most part it seems to stop leaking

How long has your 1999 Ford Expedition had this problem?

few months