Coolant leak at radiator cap

[pc124]

When my temp gauge says about 150 degrees, coolanat starts to leak from under the rad cap.

I have a new 'made in Italy' cap from IAP. I have a newer $5 part from Checker Auto that seems to work better.

Has anyone been thru this? Is there an inexpensive/easy fix?

My car is a '78 and I am pretty sure the radiator is original. The system seems to work well. The fan comes on at about 195 degrees, and the car runs below 190 during long drives and then back up to about 195 at stop lights.

The outlet for the hose to the overflow tank looks weak but I am sure that's not where my leak is. Leak is not severe, but not acceptable either.

Any feedback would be appreciated.

[htchevyii]

I had the same problem, my new cap looked fine but quit sealing after about a year. There are two different depths of caps, but as long as you've got the right cap and the neck is in good condition, I'm not sure what else you can do, but replace it.

[pc124]

And replacing the neck means replacing the radiator, right?

[htchevyii]

Sorry, I meant replace the cap. A good rad shop could replace the neck, but I don't know if it'd be worth it unless the rest of the rad was really good.

[kilrwail]

Replacing the neck is not expensive - it's all soldered brass and rad shops do it often. Probably less than $50, including a matching new cap.

[bwilson27]

Just get a cap rated at 195 or higher, with a good rubber seal.
Also check the lip at the radiator opening for dents or dings.

[htchevyii]

Just get a cap rated at 195 or higher, with a good rubber seal.
Also check the lip at the radiator opening for dents or dings.

195? seems a bit high isn't it more like 12 or 14 lbs?