Got my new truck and got questions

[agjake11]

Just moved up to an 04 f250 Friday night from my f150 and so far love it aside from one issue. It's an 04 crew cab lariat 6.0 fx4 short bed. Motor is mostly stock and has 169k on it and a straight exhaust after the cat (for now). Leather and paint are in great shape and I put my 08 tails I had on my f150 on.

My issue is the 4x4 shift on the fly isn't engaging which I found out when we got to the beach today. Thought I heard it click when I test drove it but guess I was wrong. I was wondering if y'all had any suggestions are where to start and if I need a new thread for this just let me know. The other thing is odd to me that when I switch to 4x4 the lights come on but the a/c is changed from blowing from the dash to the defrost vent??

Anyways heres the truck





Look forward to hanging out and learning more about the diesel world.

Jake

[pizza pig]

this truck was ebay right? nice purchase!


the non functioning 4x4 is a vacuum leak, the system/hubs are all operated by vacuum. Its a very common problem

[agjake11]

i found it on cars.com actually and it was local so we went to the dealer.

any info on how to fix it or where to search. this is my first for alot. first 4x4, and diesel

[bismic]

Most common leak points:
Heater control valve (if so equipped)
4x4 solenoid - passenger side
Hubs
Climate control system - blend door

[Lilpooh]

Your gonna need to visually inspect all the vacuum lines for damage. Sometimes the gray vacuum line up by the oil fill tube gets knocked off of the nipple on the HVAC box or if you have the inline heater hose valve.

You might as well go over the ball joints and u-joints for wear. Here's a write up that will allow you to replace ball joints and hub seals if your gonna be replacing the hub seals.
http://www.superdutypsd.com/ball_joint_article.php

Here's the gray vacuum line connection locations. This link will show the two locations.
Control Valve after Service

[Austin G]

Seeing how your AC starts blowing out of defrost, you have a vacuum leak to your hubs. That is what causes that. If you turn your hubs to lock them you will have functioning 4x4 (your transfer case is still working properly, your hubs just aren't engaging.)

[bismic]

My solenoid leaked and acted the same way.

[agjake11]

Thanks for the help so far guys I'm really glad this isn't a major issue relatively speaking.

Is it a bad thing to have the hubs locked at all times since the vac leak so I can still use 4x4 if I use the selector on the dash?

[Lilpooh]

Originally Posted by agjake11

Thanks for the help so far guys I'm really glad this isn't a major issue relatively speaking.

Is it a bad thing to have the hubs locked at all times since the vac leak so I can still use 4x4 if I use the selector on the dash?

I wouldn't leave the hubs locked in when on pavement it will rob you of MPG. If your going off road, where the backtop ends,it only takes a minute to get out and lock/unlock them manually.

At least we have this option, the Chevy and Dodge don't have manual override, if your in a bad situation and get stuck your SOL. Ask me how I know!LOL!!!

[agjake11]

Ha well guess. I need to figure out if the center caps on the front wheels come off through the back of the wheels or not and test the hubs