I'm installing my back wheel after getting a new rear tire. I'm trying to reinstall the caliper but I'm unable to spread the brake pads apart enough to get the caliper over the brake rotor. I have the parking brake cable and the return spring unhooked. I manual moved the parking brake to the front and that made the pads that much closer. Bottom line is I'm unable to spread apart the brake pads in order to push the brake cylinder in. Help, Neil