Theres this epoxy with fiberglass that works real good on plastic. I used it on my other cars radiator and it hold ups pretty damn well. I was surprised i mean i used the 24hr jb weld and that shit crap real fast but i was worth a try so head over to your local auto parts store and get it. Dont know the name of it but its fiberglass with epoxy that goes on the radiator for the plastic area.
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