found my 66 122 has the front brakes "locked up". Really tight and won't let go. I pulled off the calipers and cleaned them off with brake cleaner and the look ok. I also checked the brake lines, passenger side squirts fluid out when the pedal is depressed. Driver side has nothing coming out. I checked the hard line and soft line nearest the brake and they are clear. Should I be worried about the remaining hard line, or ???? How would I check? Can I blow air backwards thru the hard line? Could this be a clot? Any and all help will be appreciated.

Thanks, Mike