Hi Wayne

Is it cold in your part of Canada this time of year? If so this may be something to do the Parkers lube going a little thick. When overhauling my BVM brakes I normally pump some thinner model car shock oil in with a hand pump when the wheel is off. This will expand the O ring till the oil leaks through and I think this cleans the muck out. I only use a small amount of Parkers on the drum itself to stop it grabbing. It works for me anyway

Jason