I have the P491 & P0492. Pump is good, so is the vacuum line.

I was wandering if it is possible to "clean" and reinstall the secondary air pump valve? I am not sure how it works, but I think there should be a little diaphragm in there that opens and closes according to the vacuum?

Just wandering if some know for sure whats inside and if it is possible to clean with brake cleaner or something?