I was cleaning out the garage of excess crap today and found a box of old parts from previous bikes. I found a set of galfer pads brand new in the package from a few years ago. Do these have a shelf life at all? They must have been from 2005-2006-ish so they ahve a few years on them of just sitting in their package in a box.
If they're in a sealed package they're probably fine.
Think about it this way...how long do you think a set of rear pads stays on a bike? My KLR650 had 10 year old brake pads on it. They worked fine.