Loosing Anti-freeze

[rkressg]

Is any one having a problem with anti-freeze comming out of their truck along the fire wall. My dealer put a new heater core in but that did not fix the problem. It happens after working the motor hard and then shut the motor off. I let the engine idle for at least 5-min. The rad cap holds 15. 0 psi. It does not do this all the time it is only an intermitent problem. When it does happen I loose almost 1 gal of liquid. Any help anyone