i am pretty sure its just a o ring

 

When you have it off for replacing, be sure to take that tube to the wire wheel to clean off the scale and rust, use metal prep, and then at least primer and paint it.

Otherwise, you're going to have a leak that just a new o-ring can't fix.

Pop

 

Man Pops, I hope not. I just did this project today. It was starting to leak as temperature is changing. Old o ring was brittle and trash. I just cleaned everything up well, used some faucet lube on new o-ring. So far, no leaks.

 

Rub some of that faucet lube into the rust scale to retard it a bit?

Just a thought...

Pop

 

ill just swap out that 90 for a new peice.. no scaling then

 

Get some new clamps too.
Those spring clamps are great, but if they get rusty they get weak.

 

Mine did this a couple years ago. I noticed a spot on the floor about the size of a Beer can. Saw the same as in the picture.. When i went to address the issue i noticed It stopped all on its own. Two years later still nothing.. It was wierd.. But i am going to address it when i do the coolant change in the near future.