I found a leak in the back of the block near the firewall in the driver's side. It is the heater return hose. Very obvious. I tried to readjust the clamps but, I do not know if that is going to be a permanent fix. My question is: Is there an "O" ring or some kind of seal on that end or, is it just the hose? Any tips?

I have seen many of the hoses pin-hole and leak.

Also, there is an o-ring on the connector going into the head.