So I just tore my ar down for a cleaning. I usually don't remove the quad rail cause it extends past the gas block and has the front sight mounted. Well I did and found that gas has been coming out the bottom of the tube/block. I should clarify, coming out where the tube goes into the block. Rifles got about 20-30000 rounds through it. Most of those have been shot with a can on. Do I need a new block? Tube? What's goin on, is the can causing too much pressure or something? Heat?