Releaserustedbolts

Options for releasing rusted bolts include:

• kroil
• penetrene
• diet coke
• diesel fuel
• pb plaster
• ATF mixed with acetone
• Fluid Film
• heat
• cool
• tighten slightly
• tap the bolt to set up vibration

Or some combinations of the above

Source: http://www.garagejournal.com/forum/archive/index.php/t-160517.html