My 2006 manual Rubicon was not driven for about a year while I was overseas. After I returned, both rear calipers had locked up. I drove half a mile, and the discs and the wheels are both not touchable after, they're that hot. I replaced both rear brake calipers, and the issue seemed fixed. Then the brakes locked up again. I'm at a loss. Could there be issues with brake solenoid, or with the lines? Any help would be appreciated. Thanks in advance.