My 25-year-old smoker had just not been working all that well for a couple of years.  It is an older style from Mann Lake, and the bellows assembly is still available as a separate unit….so I finally decided to replace it.

But upon taking the old pumping unit off, I found that the bellows-hole where air is expressed into the burning chamber was occluded by years of smoke and ash. In the photo below, it is marked with a red arrow—and notice the extra bellows to the right of the smoker.

After cleaning out that hole, I have a fully functional smoker again.  And until the plastic cracks, I expect that my old smoker will keep on working perfectly as it is.