Are you sure the noise is coming from the hyd. brake pump/actuator? I don't believe it should be running if the brakes aren't activated. Mine doesn't come on unless the brake pedal is pushed or the breakaway switch is pulled. Sounds like something is wrong somewhere. The noise isn't coming from the transfer switch is it?
2012 FORD F-350 SRW CREW CAB 6.7L DIESEL
2016 PINNACLE 36FBTS