My new to me dump truck has push pull air valve with a label that says diverter valve. It doesn't appear to be a factory valve but I'm not sure what it does? I thought it might be to lock all the wheels like a diff lock but not sure.
First guess would be it's set up to pull a pup trailer, will have a hydraulic quick disconnect near the hitch for connecting up the trailer's dump cylinder. You flip the air valve and the air shift diverter changes oil flow from the truck's cylinder to the trailer line, then the dump control works the same way up and down.
Thanks. It's pulled out and is the same kind of control used for the air cylinder for the tailgate. It makes sense it's for another function as the truck used to be a plow truck and the dump box is made to come off, I assume to put a sander on. It still has all the sander controls but a lot wires and stuff have been cut or disconnected. There's a 3 spool solenoid hyd. control but only the dump box is hooked up. There is a big pintle hitch on the truck and it has the air control for trailer brakes so I think it's something air related.