i play a conn 6d and one of the valve bumper/pad things fell off. i have no idea where to find one or how to search for one. please help!

Go to your local repair person music repair shop. It's not worth the trouble to try and find it online. They can put it in right away and trim it.

For future reference if you want to keep some stock on hand you can get some through Anaheim Band Instruments. They will sell you stock (this is assuming you know what you are doing).

Here is their website, call them. Understand different horn take different size bumpers, someone there should know what size the 6D takes.