I had a hard time with this issue. I scored in the 91st percentile on the PCAT in 2003. I had a hard time finding schools that would accept scores that old and from before the test changed. I did retake them in Jan but I had most of my interview invites before the new scores came out. Some schools do have a 5 year rule. For the other schools, it seemed like just a formality.
The maximum I've seen is five years unless the school doesn't care at all. However, many would like scores that are more recent like two years ago. It varies per school so it's best to keep track of the differences between schools.