As Karl said, the plastic used in the reservoir will not play well with most epoxies. 3M makes an epoxy particularly for these types of plastics (Scotch-Weld DP8005), but at $45 / pack you'd be better off sourcing a replacement reservoir.My '86 has developed a leak in the coolant expansion tank. It's in the "hole" that holds the 2 halves together. Now is not the time for me to replace this, so I'm wondering if filling the hole with epoxy would work. Anyone have any experience with this - or a similar fix?
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Sure seems like the time to replace it. Trying to fix it will likely lead to disappointment.Now is not the time for me to replace this