UH are you sure about that? Disc brake conversions are hydraulic powered by an electric actuator. Unless it was pulled by a class8 tractor that already had air brakes no one in their right mind would go with air/hydraulics. If it truly is air/hydraulics then it should be as simple as swapping the actuator out to the tune of about a thousand dollars.
Hey ramdualydude, if the trailer has hydraulic brakes it might have the Dexter E/H 1000 brake actuator which works off a regular electric brake controller.(except some GM factory units).Check online at Dexters website and down load operation maintenance service manual.Look over your trailer to see if it has this unit.I hope this helps.If it is straight air over hydraulic it will have air hoses&connectors.let us know what you find out.----LOU---