I'm not familiar with that one , but it states it's formulated for "rubber" gaskets. I make my living as a mechanic & regularly use Permatex products.
their Avation gasket sealant is the one I'd use for a stubborn leak. It'll be harder to clean off on the next go round , but it should cure the problem you're having now. Degrease all the surfaces well with brake parts cleaner, before you apply to both surfaces.
Good luck with your repair ))