About two weeks ago I heard the air "pop off" ocasionally, never heard that before, thought it might be the governor going bad.... Last week it became more of a regular thing...tracked it down to the safety valve on the air tank... The governer must not be unloading the compressor...I took it out for a spin on Monday and it was popping off every couple of seconds... okay, back to the house, gotta replace the governor... Go down to my friendly neighborhood parts store to get a reman bendix...owner says they last about 13 months (mine is almost 18 months old)... $18 for the governor Install it get everything taped and tightened...WTF? Doing the same thing?!? After a little head scratching I notice the governor line to the compressor has been rubbing on the frame and looks to have a small hole in it, Aha!... I convince myself that is why it was failing gradually, as the hose wore on the frame...makes sense Back to the parts store...can't bring myself to pay 45 cents/inch for steel braid so opt for plastic hose and new fittings... $8 for 3 feet tubing and two fittings... Get the hose routed all pretty and away from the frame, everything looking peachy...WTF? It is still doing it? Okay, now have worn thru my scalp scratching my head...lets see, when the high "set point" is reached, it passes air to the unloader, okay, lets pull the line off of the governor (truck running) to make sure the compressor is getting the signal, maybe the unloader is bad, Yikes! F'in radiator brace precludes easy access to the fittings so off it comes again..hmmm, no air coming out? Being fed from the manifold, manifold feeds the gauge, gauge says 130?!? Could I have gotten a bad governor? WTH, lets put the original one back on, cause if it was the airline leaking, the orginal governor might be good...change out the fitting and retape all of the plugs and reinstall...WTF? It is still doing it!!!! Sit in the cab with the engine running contemplating hari-kari,,,,wait a minute, it is popping off just under 130, shouldn't it be 150?!? Go back to the tank an hold the safety valve in, it takes about 1/2 second for the compressor to unload...this mutha#%$%^#$$%SOB! Back to the parts store for a new safety valve, $8 more dollars... Of course this solves the problem! So I gained considerable knowledge and learned a valuable lesson and it only cost $34!! Even better, Truck is back on the road!! PS...I also went thru and taped and hung all of the fuel lines that were close to rubbing...