Vacum question
 

After having to have a valve cover gasket and wiring harness replaced in Cody, Wy. on my 2003 7.3. My A/C goes to defrost for a few seconds, before going to A/C. Could there be something around the valve cover, that was left loose, or just a coincedence and the hub seals are going?


Thanks Jim

Your vacuum comes from a pump on the passenger side firewall. It would be real easy for you to checkif it was the hub seals by simply disconnecting the hose to the hubs, put you finger over the line, and have some one select A/C.

By the way, you don't get vacuum to the hubs unless you select 4x4.

Good luck!

Hey Jim. We need more info. Is this at startup or when you put it in 4x4? When does this happen, and what are you doing at the time?

It is when you turn on the A/C, or at start up. 4x4 not in use.
Turn on the A/C. Mode switch in A/C or Max A/C. Defroster comes on for a short time and then slowly the door will close and the air then comes out the A/C vents.