no 4x4, and defrost mode

[rollingrock]

Hey experts

Headed back out to the ranch this weekend, the ranch is getting lots of rain which means i need my 4x4 to work on my 06 6.0.

So last weekend I almost got stuck b/c my 4x4 didn't engage, I had to get out in the mud and lock the hubs. Not fun. A mess really.

So this week I tried to fix it myself. When I checked the hubs with the Mighty Max hand pump, I can get 20lbs to hold for several min with no drop. I also ran the pump and it was pulling 11 lbs to lock and 8 to unlock.

So I felt that I should replace the pump and the PVHS (pulse vac hub solenoid)

Rechecked and got more vac, 14 on lock and 10 to unlock.

That all said...when I put it in 4X4, my vents go in to defrost mode.

What am I missing here?

Thanks for the help folks. Heading to the ranch on Friday afternoon to get some work done. If I can keep from getting out it would be great.

I will have Mighty Max with me so if I need to check something else yall recommend, i can give it a try

Cheers

RR AKA Jason

[late_99_PSD]

Sounds like you got a leak somewhere in the hub vacuum lines from the resivor to the hubs.

[rollingrock]

Originally Posted by late_99_PSD

Sounds like you got a leak somewhere in the hub vacuum lines from the resivor to the hubs.

Is it possible that the reservoir is bad?

[late_99_PSD]

Yes, but then you would probably notice it all the time.....

[rollingrock]

Originally Posted by late_99_PSD

Yes, but then you would probably notice it all the time.....

Ok, thanks

Is it necessary to get the Ford OEM air lines or can I build my own?