vacuum leak / 4x4 hubs

[elite51203]

My hubs will not engage unless i get out and manually lock them. transfer case works fine. Ive noticed that my a/c is blowing through the defrost vents. Im sure that i have a vacuum leak but I crawled underneath the truck and looked everywhere for the leak but is still cant find it.

The end of the vacuum line going into the front hubs was brittle and broken, but when the vacuum pump was running i didnt feel any vacuum suction from those lines at all. Ive pulled lines off of the vacuum pump and they have suction.

Im tired of getting out and manually locking the hubs. I just want the 4x4 to work like it should! I just cant figure it out....!

[Tmoney511]

Originally Posted by elite51203

My hubs will not engage unless i get out and manually lock them. transfer case works fine. Ive noticed that my a/c is blowing through the defrost vents. Im sure that i have a vacuum leak but I crawled underneath the truck and looked everywhere for the leak but is still cant find it.

The end of the vacuum line going into the front hubs was brittle and broken, but when the vacuum pump was running i didnt feel any vacuum suction from those lines at all. Ive pulled lines off of the vacuum pump and they have suction.

Im tired of getting out and manually locking the hubs. I just want the 4x4 to work like it should! I just cant figure it out....!

Have you checked the solenoid on the passenger side fender under the hood?

[dr8082]

Brother I share you pain. I too have strugled with the same problems. If it helps I have talked to many people and came to the conclusion that it does not hurt to run the hubs locked in and the t case in 2wd. Atleast for short or around town driving. If Im going very far like a 40 mile trip or more I unlock.

Good luck.

[elite51203]

Im not sure where this solenoid is....would the pump still operate if solenoid is faulty? The vacuum pump does still kick on....

[Tmoney511]

I am having the same issue that you are having. If my hubs are in the "auto" position and I switch to 4wd high my front drive shaft spins but my front tires don't and I'll get stuck in sand but the moment I get on pavement and turn my front end hops. I turn the switch back to 2wd and I turn on pavement my front end doesn't hop. When I turn my hubs to the "lock" position and then turn my switch to 4wd high or low my system works. I checked all my lines and I have no leaks. I checked to see if I was getting power to the solenoid and I was. I haven't checked the solenoid itself though. If you pop your hood look at your passenger side. You'll see a white box. That's the solenoid.

[goose5]

The pump will still operate with the PVH solenoid not working properly, just out of curiosity is your hvac system stuck on defrost?

[iskwezm]

I had the same issue this past weekend in Pismo. Put it 4WD and got stuck, looked kinda dumb till somebody said the fronts werent engaged. Once it was locked it was fine. But i did a 4WD launch on the street and it left 4 LONG black marks.

[hornythrony]

My father in laws 05 has the same issue has anyone gone into the hubs to see what the vacuum works and to see if that piece works?