I have a 95 V6 Runner and have a leak where the upper radiator hose housings come together. I removed the upper hose and then the 2 nuts that held the upper part of the housing together with the lower. The upper housing has a groove in it and what looked to be a rubber gasket or oring as well. I took it to a parts store and they said no part existed just RTV it. That will probably work but why would they make it with a groove if it didn't have a oring or something for it?? Anybody have experience with this?

 

I just recently did a complete over hall of my cooling system. They're right, No gasket exists. you simply have to seal it.

 

Yup, you should use RTV or FIPG.