I replaced the heater core and blend door over the weekend and much thanks to those who posted tips here. The job was better then I thought it would be. I did have one brain fart putting the heater hoses back and actually put one together by installing the plastic clip, 2 o-rings and backing ring on the heater core and getting hose to clip it. Was a bear and I then realized I could "load" the hose and snap whole assembly to the heater core. Duh for me. My only question is now it seems like the cooling system never builds pressure , even when truck is hot. I am not totally sure how it behaved before though. The temperature runs normal , seems to be no leaks and heat seems fine but it worries me slightly the system never builds pressure . Is this normal/typical?

 

ttt...anyone?

 

Have you put a cooling system pressure gauge on it or are you judging by opening the cap?

 

Not sure how to put a gauge on it. I am judging totally by "feel" , that is collapsing upper rad hose. I expected it to behave like that for 1st temp cycles since the cap was off until thermostat opened, not I would expect some pressure to build.

 

First the pressure gauge goes on the radiator were the cap would go or for the F150 it goes on the reservoir tank. It is a cap with a pressure pump and gauge attached. You will not have any pressure until you put the cap on, without the cap you have a open system.