Suspension air bags deflating

Have a 2013 IH 8600 with MF 11. Searched all over this forum and can’t find a similar problem/cause. After engine is shut down then restarted, the rear air bags inflate and susp/dump switch is solid green. Within a few feet or after any tiny bump, they deflate and the susp/dump switch blinks. Won’t inflate again until engine shutdown and restart. Pulling out what little hair I have over this one. Solenoid panel was removed and cleaned and both solenoids replaced because of air leaks in the push air line fittings. Horn works so ground should be good. Rear leveler was also replaced. When the switch is blinking there is no air supply to the rear leveler. Couldn’t find the body controller, removed the instrument cluster and didn’t see it. Maybe related-air psi builds to 135 but when compressor kicks off air drops to 120 in a few seconds in #2 tank. #1 tanks drops slightly and overnight both tanks are at 30 psi. Compressor runs way too much. Compressor and governor are also recent installs. A couple bottles of soap mix and I can’t find that air leak. Any help would be appreciated!'

 

Thanks PE-this truck has been converted to a water truck but the trailer air lines are still there. I’ve isolated the water valves/PTO air supply from #2 air tank with no improvement. Plugs are in the fittings that supplied the trailer air behind the cab. What’s confusing is the #2 tank drops to 120 in 10 seconds after the compressor builds to 135 and shuts off. I would think you could at least hear that. Found a couple small air leaks and fixed them. Had the dash apart, parking brake valves exposed and removed air filter assembly to get a good look/soap at all air lines entering the firewall. Maybe plug the air tank fitting that supplies the trailer brake system? Don’t know how that may effect the vehicle braking air system.

 

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Found the air leak-purge valve. Susp dump valve is solid after restarting engine but badges still deflate and switch blinks after the slightest bump. Body controller looks clean and no wire fraying. May be time for the dealer, which is going to be costly! Thanks for your input PE.