Didn't read all of the threads but if suspecting a mechanical failure of a shock or shocks, Use the suspension height to go back and forth from access to off road a couple cycles, Then leave truck at rest at Normal height and pull #3 fuse, a 5 amp fuse in the engine bay fuse box. This fuse controls the self leveling which asleep system. Measure all corners from the cent of wheel hub to the fender flare, then let set 24-48 hours. Remeasure if one corner is lower then the others you found your issue, If front pair or rear pair are lower then either both rear or front leak, probability of two failing same time is unlikely, so Then I would check the rear or front valve if not previously rebuilt.
Use U tube and look at the videos from 4x4airseals, for rebuilding valves, if needed. Guy on there also shows how to do compressor rebuilds. Very good info.
Mine turned up right front when I suspected right rear. But since mine were OEM from 2005, I dug deep and replaced the three old ones as the left rear was replaced in August by a tire shop who poked a hole in it. No charge.
The issue is that sometime a small leak will be hidden due to pressure on the cuff from the shock. I had replaced my compressor there fore the system had deflated, then my leak became apparent/ I had washed a gallon or so soapy water all over the system prior to that to find a leak and it showed nothing.
So now I have a complete system back up once I rebuild my old air compressor exhaust valve seals. Saved the rear and left front shock for emergency spares, and also got valves, front back and rear, so I can switch those in a pinch and rebuild the old one as needed.
I hope I'm set on suspension failures for a while.
I went with Arnotts, Lifetime warranty, and have not heard my compressor even run for a while, which is weird but I guess the shocks with no leaks are staying at the correct height. Not sure why but I also gained one mpg on the highway as I have a 5 hour trip one way on weekends to get home, 5 hours back on Sunday night
