This is from the service manual. It is possible that the self adjust mechanism on your ebrake pedal isn't working, I have seen that before. Only repair is to replace the pedal assembly
PARKING BRAKE CABLES ADJUSTMENT
The park brake cables on this vehicle have an automatic self adjuster built into the park brake pedal mechanism. When the foot operated park brake pedal is in its released (upward most) position, a clock spring automatically adjusts the park brake cables. The park brake cables are adjusted (tensioned) just enough to remove all the slack from the cables. The automatic adjuster system will not over adjust the cables causing rear brake drag.
Due to the automatic adjust feature of the park brake pedal, adjustment of the parking brake cables on these vehicles relies on proper drum brake (Refer to 5 - BRAKES/HYDRAULIC/MECHANICAL/BRAKE PADS/SHOES - ADJUSTMENTS) or park brake shoe (Refer to 5 - BRAKES/PARKING BRAKE/SHOES - ADJUSTMENTS) adjustment.
When the park brake pedal is applied the self adjuster is by-passed and the pedal operates normally to engage the park brakes.
When a service procedure needs to be performed on the park brake pedal or the park brake cables, the automatic self adjuster can be manually locked out by the service technician.