The windshield washer fluid tank on my Toyota Corolla has a C-shaped crack in the bottom. I removed the tank and drained it. Is there a reliable way to patch/fix this without having to buy a new tank? (I'm thinking of trying to patch the crack with silicone caulk.)
I fixed a leak in my coolant tank (which is the exact same plastic) using a few strips of plastic* cut from a spray bottle I bought at a hardware store. You can either use a heat gun or a soldering iron to melt the plastic into place. Just be careful of burning the plastic.
This video is a good guide. Even though it's a much larger tank, the technique is exactly the same.
It's definitely possible. My choice for a repair like this would be JB Weld, but I would think lots of products would do fine, though I'd be skeptical of any kind of caulk that's not going to bond tightly to the plastic.