Hardtrigger, on my 1992, the top gauge is the transmission air shift pressure gauge, the center gauge is the system pressure gauge (non-adjustable) and the lower gauge is the tag axle air. To adjust the tag axle pressure on mine you pull out on the plastic knob and rotate. Assuming the engine is running, the gauge should change with a small movement of the knob.
If you actually have 125 psi in your tag the rear of the coach would look high and the rear wheels would have very little weight on them. I would check for a stuck air gauge. Does the gauge drop to 0 a couple of minutes after you release the tag dump switch on the dash?
|