[rich weyand]

So? Pile anything heavy on the driver side. Things don't always settle the same.

You should inspect the drums and shoes, and change the shoes and machine/replace the drums if they need it. Also inspect brake lines and cylinders for leaks, dry rot, etc.

I also ended up replacing my master cylinder, because the little rubber cup on the end of the piston had age hardened. If the pedal slowly sinks as you hold the brakes continuously while stopped, that's the symptom I was seeing.