the balls came from the baring that runs on a sort of "up and downie" track on the timing device that pushes the diaphragm in and out to produce vacuum. the pump would not work without this baring. if your pump is working OK then I think we can assume the failure happened before you got the car and the pump was replaced. Do you have a manual, Haynes is not bad and covers most things pretty well or the CD from eBay is cheap and helpful if you can figure out how to find anything on it.
Steve

"Zoonhollis I swear they are not mine!"

" Stevo Humm...why would anyone think they might be
"