GTA back brakes Problem

I have a 1988 gta with 10600 miles on it with a 350 efi. It has rear disc brakes and posi. I went to get a sticker on it last fri and the guy said it had no back brakes. This was found out when it was put on the rollers for emissions. We lifted the cars back end and indeed there was no back brakes. The held when the was off moving the wheels. But with the car running and in drive the wheels would barley stop no matter how hard you push. We checked for air in the line and there was none and the caliper is moving when you push the brakes. If you push the brakes and open the bleeder fluid come out real quick so it seems like there is no cloged lines. These are rear disc brakes with a lever on caplier for the emergency brake. Also the emergency brake does hold the back tires still but if emergency brake is up and you push the petal for the brakes rear tires start to move. So now im confused? Back pads are a year old or 2 rob