what would be the sign of a bad radiator cap?

My problem is that i just finished my hose job and i have the problem that everytime i let the car cool down, the coolant gets low in the radiator. Although, when i look at the level on the plastic tank on the passenger side in front, i am way over the full limit.

what could be causing that?

should we see a spring in the radiator cap?

And no, there is no leak, i checked oftenly. It doesn't seem to be any in the oil since the car is running strong.

thanks a lot

puma

 

oh and also, what about the cap on the ast. It written to never remove it but is it like the sticker on the air-pump that says never remove?

 

c'mon, i know someone know this or has already seen it's radiator cap.

 

someone else posted these same symptoms - in their case, the AST was cracked.

 

the cap on the ast is the actual "rad" on a fd the one on the thermo neck hosuing is just a fill cap, hence no spring...on the ast it only says do not open while hot wich is the case with any rad cap....

rad caps are like 8 bux, if u have any doubts in it its better off to get a new one and trouble shoot from there...

how mnay miles on your car...coolant being pused out of the system into the over flow ant not being recovered is a sign of bad coolant seals....hope its justa bad cap, or pinhole in the line