I installed the coolant filter on my truck. Everything went great. I lost a little coolant doing it but not much. I filled it up with some extra to bring it back to where it was before. Everytime I check the level its on the MIN line. no matter how much coolant i put in there. I filled it with a little coolant a second and third time just to see what its going to do and it went back down to the min line. I know that the min line is where its suppose to be but aside from that where is the coolant escaping from. I have no leaks. I have an 04 f250.

 

How much coolant have you added? A cup or more? Does the cap let out pressure when you loosen it warm?