My compressor passes the D2 regulator test in that with the engine running, when pumping the brakes, it cycles between 80 and 120 PSI.
But..............
Going down the road the white needle gets ahead in pressure loss by about 10 psi. At white needle indicated press of about 100 psi the air compressor then starts and builds the air pressure in both systems back up 120 psi.
It takes about 7 or 8 minutes to do this.
Static leak; both system bleed down together and will hold above 100 psi overnight with the level system on.
Over 3 days setting with level system off it still has 40 to 50 psi
Bill,
Sounds fairly normal to me. When driving, my pressure gauge needles rarely stay exactly together. If I remember correctly, the red needle is "Front" tank, and white needle is "Rear" tank. Suspension may be working harder at one end or the other, trying to keep things on an even keel. Perhaps you need to slow down going around those corners! :))
Bill,
What about a ride height controll valve leak when the valve shaft moves while traveling?
JD