John...
I have not had this particular problem, but have had to rework the emergency brake system which had been installed incorrectly on my car.
I assume you have standard drum brakes on the rear axels.
The quickest adjustment procedure is to back off the adjustment nuts at the lever, then adjust the brake shoes {slight drag}. Then tighten the nuts until 3 to 5 clicks engages the brakes.
While under the vehicle check the two clamps {one on each wheel} that
hold the cable housing to the backing plate. they should be ridgidly held on with a single screw each. Also , if your cable housings are not cable tied to your trailing arms / spring plates adjustment can be difficult
I hope this helps......
Staying tuned for your further adventures....
Leon Chupp