Toyota Repair: 92 celica, radiator cap, sorry cant

Question
just bpought a 92 celica from private owner - drove car 3 days today i park the car and it seems antifreeze is leaking out. I filled it up drove it - doesnt leak until I park it and then it makes a hiss sound- help!

Answer
First I would start out making sure the radiator cap is good. They are pressurized to increase the boiling point of the water so you may want to check it. Secondly, look for the green or wet area around hoses and connections. Also, look over the radiator and make sure there are no cracks where it could be loosing pressure. Sorry cant be more definite, but any of a number of leaks could be possible.