when i take my truck on a longer trip the clutch pedal will get so hard you can barely push it in, and when you do it doesnt want to come back up....did it since it was new.....any advice?

Is this a Duramax w/ ZF6 trans? If so check in the ZF6 forum part of diesel place. There has been tons of talk about this. Something along the lines of the Clutch fluid gets really hot from the trans heat.