My friend had a '94 F-150 straight 6, and has had a clutch problem that has happened 3 times. When he leaves to go out of town for business he leaves his truck at home, which sits for 3 to 5 days. When he gets back he can drive the truck just fine, but the next morning the clutch is stuck in gear and we have to bleed the line, which has lots of air in it. All the times the exact same situation has happened. Does anybody know what the problem is and how it can be solved??? Any help is much appreciated. Thanks!