When I turn to the right sometimes the rear drum brakes engage without me touching the brake pedal. The brake fluid resivoir is full. What could be causing this?

 

worn rear bushing in the rear is allowing sufficient play to cause the ebrake cable to catch on something and pull during turns
The steering mechanism is not connected to the brakes. So that's my thinking. Seen it before.

 

Can you 3d print him a bushing?