Radiator Leak when heater turned on?

Hey everyone
I just bought a used TT v6 2003 and everything seemed ok until last night. It got cold here in new york so I put on the heater and left the truck running while I ran in the supermarket. When I came out there was a puddle of antifreeze and it looked like it was leaking from the radiator passenger side. I drove right home and the truck had what looked like steam coming out. I also thought the heater had died as it was no longer very warm in the truck. Any thoughts? thanks
RAR

 

Whats the question?

If the rad's leaking, inspect it. Check all hose while you're at it.

Replace it and bleed air out of the system.

 

I just wondered why I had no problems until I put the heat on or was it just a coincidence?

 

I suppose it could be the heater core leaking. Or the valve on the firewall. But then it would have a distance to run to get to passenger side of radiator.

 

ok i remembered there was some sort of valve at the firewall so I was wondering. Thanks

 

You were leaking before, just had not noticed.

 

Nothing ever breaks until you use it...your heater core, or the plumbing that supplies it, is leaking.