Pinhole leak in plastic under radiator cap - is there a fix?

[hc803]

Noticed a bit of coolant under my 2004 SR5 the other day, borrowed a pressure test kit from national chain and discovered this very small but definite pinhole leak in the plastic part of the radiator right below the cap. Is there any true fix for such a problem or am I looking at a replacement radiator?
Thanks in advance for any suggestions.

 

[Hi-desertT4R]

JB Weld Plasticweld. World's Strongest Bond | J-B Weld
My buddy used this on his radiator tank in his Avalanche and it held up over a summer in the Mojave desert. He used the two part epoxy tube not the putty. It might be worth 10 bucks or less to try at least temporarily till you get a new radiator.

 

[hc803]

thanks, I was looking at that stuff earlier. will try that first.

 

[MikeinNH67]

I think any sort of epoxy will be a temporary fix but couldn't hurt to try seeing it looks minor. Jb weld is good stuff, check out Projectfarm on YT for tests on each type. Clean and scuff up the plastic before hand. Also once clean make sure it is the plastic leaking, is it cracked or somehow a pinhole? One thing to know is these kinds of rads can seep where the metal attaches to the plastic as the gasket gets old so may travel to the area you see but it looks more like where the cap section melds into the lower section.

 

[gaber6]

Radiator is relatively cheap fix for something that's a pain to fix when it is zero degrees or 115 degrees. That said, I'd probably try melting the are with a soldering iron and patch plastic like PTFE we do to fix ski bottoms. Who knows if that would work.

 

[Drcoffee]

If there is one crack, its probably not the only place it has fatigued. Especially near the filler neck. Just replace it with a new radiator from rockauto. As you go into winter, the wider temp cycles will accelerate the cracking. At 15 psi, epoxy is not a good fix on plastic tanks nor is a radiator sealer because of the flexing of the plastic tanks. For $170 you can drive worry free for another 200k miles. I prefer TYC or DENSO