Hyundia Elantra Coolant leak...... How to Stop it

Retourqued the hose clamps on the engine side then something wierd happened. The leak stopped on the engine side just to start on the radiator side. I tourque the radiator side as a quick fix but I am starting to wonder if the pressure cap may be worn - not allowing the coolant to return to the reservior when the system is over pressurized.

Thoughts?