Another air pressure thread...

I recently had Cat change my clutch. After I got it back it had multiple audible are leaks on lines going to secondary tank.. I was informed the tech had to drop the tanks to do the clutch and to bring it back and they would address it. Took it back and they dropped tank again and fixed it, replaced a couple fittings etc. My problem is now when ever the truck is moving my air fluctuates from 125 to 100 and back up in both tanks. Mostly the secondary tank.Not a fast sweep down, like a slow leak then the compressor refills. If i sit still idling it maintains 125psi and never moves. Release brakes, with chocks, idle it and it stays at 125psi... As soon as i start getting down the road it starts fluctuating.It didnt do this before the clutch job and tanks messed with. Any ideas?? Something has to be hooked up wrong, maybe a check valve or something, i dunno....