fil neck cap is blowing off
 

got a weird problem.
old radiator was crap so got a new aluminum one.
now my fill neck cap is dripping water even if the water is not hot at all.
i have even tried using a freinds cap and same problem.
finaly i bought a 16 psi cap and it is loosing water at high engine speeds.


whats the deal here?
i have eve tried runing the car with and with out a thermostat.

blown coolant seals pushing the coolant out.