Brake question- Driving the Challenger and noticed a front brake dragging. Eased it home and ordered a set of calipers from Napa. Bled it out today and both front brakes are tight. Checked the metering valve and the pin is not moving when the brakes are applied. I can tap it in and it comes out when when brakes are applied but doesn't go back in on its own. Seems like I took it apart and cleaned it when I built the car 15 years ago. Does this sound like a metering block issue or maybe something else? 70 RT with disc brakes.