1) what level should I fill the cooling water reservoir tank up to? I have given different answers. Fill to the top or fill to about an inch (1/2 of index finger) to the top?2) my delivery captain told me to fill the reservoir with water. Shouldn’t I fill with 50/50 water and antifreeze? Or maybe top off once with water and next top off use antifreeze to try and keep the mixture close to 50/50?3) Does the reservoir end up being pressurized when the coolant is hot like a car radiator? It should only be opened when engine is cool? 4):Where does the coolant go? I did a 35 hour delivery run. At the end of the trip both engines cooling water levels were about 1 inch down. I have 1988 67’CPMY with DD12v71Thoughts?Thank you