vacum leak?

[blackbullitt]

ok so i noticed my 4x4 not working a couple days ago. so i wasnt sure what it was but today i tried to change the setting on my air from defrost and the floor to coming out the vents in the front of the dash and it didnt change. so i continued to try to changer it to anything and no matter what i do it only blows out the defrost and floor, even when i set it on AC. also i have the manual turn nobs if thats what you call it, not the digital climate control thanks for the help

[forddieseldoctor]

Does your vacuum pump run at all? Does it run continuously? If it runs continuously then you have a vacuum leak.

[choupique108]

what if it doesnt run continuously and it still dont engage 4x4?

[forddieseldoctor]

does it run at all when you turn the key on?

[blackbullitt]

im not sure? how do i tell if it does run? the only thing i hear when i turn the key is the extrnal fuel pump and the glow plugs

[06pwrstrokerbullitt]

Ive had this problem a while and still haven't figured it out. No auto 4x4 and climate control only works on defrost. Vacuum pump seems to work fine it fills up and holds the vacuum fine??

[Stoker0560]

mine did same thing..no 4x4 no vents..pump ran constantly.. to tell if its running turn the key on and pop the hood..its on the pass side fender well..it noisy cant really miss it..should shut off after a few seconds..i traced mine to the "front hub 4x4 vacuum actuator" or some silly name like that..its on the pass side fender near the pump..its a smaller gizmo with two vac lines going in the bottom..(both are connected) and has a lil wire harness plugged in at the top..mine was leaking. i replaced it..fixed my vent problem and the vacuum quit running constantly, but 4x4 still didnt engauge at the hubs..turns out bad hub seals..really common problems, have yet to fix it..