F350 4x4 Vaccum Solenoid Broken?
Guys another 4x4 thread. I need clarification for my diagnosis. I have cheked all hoses for leaks going from the solenoid to the hubs and what not. Everything is good. I vaccum cheked the hoses and if I switch to 4x4 it jumps to 14 but goes right back to zero. So I went all the way back to the little compressor that goes into the tank and from there to the solenoid thingy. I cheked the red hose which is for the hvac, which holds the pressure. What I have learned is that the vaccum going to the hubs has to hold for atleast 20sec or so to engage the hubs and will release once the hubs are locked. So im thinking I need to replace the solenoid switch correct?