front brake issue since caliper removal

A friend and I are working on a 1983 KZ550 LTD. We replaced the fork seals and as a part of that process removed the front brake assembly from the fork / rotor. When we took it off, we stuck some cardboard in there to keep the caliper open. While it was off we were careful never to pull the front brake lever.

When we went to put it back on it was a very tight fit. He managed to cram it back on, but the pad is grinding on the rotor on a spot every rotation.

Our inclination is to bleed the brakes and see if that relieves any pressure on the caliper. (The fluid is old and could use it anyway.) Are we headed in the right direction?

Thanks.

that would be a good starting point,if that doesnt do it id pull the caliper off to make sure the pad isnt twisted somehow

roger that

Chances are,when you were "Cramming" the caliper back on,you might have snagged the edge of a pad on the rotor,and broke a crumb off,and now it's wedged it between the pad and rotor.
I'd pull it off again,and clean the pads,and try it again,but this time,take a c-clamp and compress the piston in so you can just drop the caliper back into place,without any force.

And just for info in the future. There's really no need to worry about applying the brakes when the caliper is off. If it happens just insert a large screwdriver in between the pads and lever them open. Even if you don't accidently apply the brakes, do this then the pads are open and slide right over the rotor. First tug or two of the brake lever and the pads close up. Also some drag is normal, everything that I own with disc brakes has some noticable drag when spinning the wheel and I'm relatively certain I don't have messed up brakes on all 12 vehicals or so I own, nor the previous 50 that all dragged somewhat.

working on it tonight - will report back. thanks.

I like using a "C" clamp to compress the piston. If you turn the clamp slowly you can compress the cylinder all the way in--which provides ample room to install even brand new (thick) pads. Just watch out that when you are compressing the cylinder, that you don't overflow your reservoir and get brake fluid on your paintwork. Keep an eye on the fluid level as you go.
A medium C clamp enough to go over a 4 or 5 inch piece should work fine.