Cusser
+1y
Yeah, pull the rear drums and take a look-see. Use the good side as a template. I doubt that it's a bad wheel cylinder, but can't rule that out. The driver side has the bleed valve, passenger side wheel cylinder doesn't.
Two 8.0 x 1.25mm thread bolts will help extract the drums. You may need to retract the shoes through the access oval if they are dragging on the drums.