1983 GL1100 Brake Pedal Issue

The rear brake pedal does not return after application,have checked master cylinder to make sure it was vented,also lubed the pedal.

I'll assume that you have a drum brake in the rear, though correct me if I'm wrong.

In either case, disc or drum, check that the caliper is not sticking. If it is a drum you could very well have a broken spring inside. Look around the brake and on the wheel for excessive brake dust. If you have it, the brake is dragging. Also you can try rolling the bike backwards and applying only the rear brake, someone to help push would be nice. Repeat this several times in an attempt to self-adjust the rear brake.

Good Luck