Help with Coolant Level

[MPD56]

Can anyone tell me where your coolant level is on the coolant reservoir tank when the engine is cold (70 degrees).

My F350 Job3 was brought in May 2009 with 12,000 mile to have the radiator changed this is after I had brought it in 5 times over a year to get coolant added and finally told them that I know where to add coolant, and wanted to now know where it was going. I brought it in the next morning and it took less then a day to change out.

Since then the coolant level has never been at the level it shows in the manual or at the marks that are embossed on the coolant reservoir. I put tape on the reservoir to mark the level to keep my eye on it; the coolant level hasn’t changed in six months.

I brought my truck in for 3 things and a stuck front calliper on October 20 (Which is still sticking) and mention that the coolant levels was low since May, but the truck hasn’t lost any coolant because I check regularly when the truck is cold (70 degrees). They went ahead and did a pressure test and said that I had no leaks! But the coolant level before I left the Dealer was still below the embossed cool marks. I brought my truck back to the Dealer last week because none of the things were corrected. They checked the coolant level and didn’t add any, because the Service Manager said that if they add any more coolant it would blow out the top of the tank. If that was true, when I’m pulling a 12,000 pound trailer at 70 mph in 90 degree temperature why does my coolant level just reach the cold engine mark. Sorry about the length and rant, but I no longer have faith in my Dealer. Because of my lack of people skills, I always get hung up on the small stuff.