Coolant Overflow

[Benelli]

Did 1979's come stock with coolant overflow resivors?

I"ve put in a new radiator due to a cracked neck on the first one. I replaced it and it works great. But now I have a constant leak from the top spout (I believe) of the coolant overflow resivore. It appears to be only 1/4 full. My pick up runs cold (Between the C mark and the first tick mark on the temp. gauge). My question, how to stop this leak? I don't like getting poked fun at because theres a puddle a few inches in diameter and the leaf spring and surrounding body has a "wet" tint to it.

If you need pictures, I can take some tomorrow when it's light. My question is, why would this be dripping and how can I fix it? It almost looks like it comes from the spout and I can feel the coolant in the spout when I put my finger in it.

Thanks.

[78 Chevyrado]

It came with a resivoir. When the coolant gets hot it expands and some of it goes into the resivoir and when it cools it sucks it back into the radiator. without a resivoir, when cold the radiator will be low until it heats up and it will spill coolant everytime you heat it up after filling it.