[rrsgsxr04]

I never comment, but this caught my attention.

OP, to answer your questions.

1. Yes they leak from the factory, always.
2. Yes, take the sight plate off and seal it with some RTV black gasket. Make sure it is properly applied and tacky before putting it back on the cover.
3. No, they're not recommended or reputable.

I'm not advocating they're a great (or even good) product. I'm just answering your question. I know a couple people who use them, and they all needed to properly seal the sight glass.

After sealing they'll work, but they still won't be as safe or durable in an accident. But you probably already knew that