question for any mechanic

[clinthwt]

Has anyone had the same issue. MY F250 will not disengage out of 4x4. At 20mph in 2wd it makes the "grind" as though the hubs want to engage. In 4x4 high it never makes another sound. I have changed the vacuum lines by the wheels, changed the vacuum pump and pulled and packed the bearings behind the brake rotors. My AC will now only blow out of the defrost
Could I have a bad vacuum line from the pump to god knows where?

[Randy]

My AC will now only blow out of the defrost
Could I have a bad vacuum line from the pump to god knows where?

Anytime your a/c does that youve got a major leak somewhere.

[bowbroadhead]

vacume pump defect or vac line , just changed mine out 2 days ago

[clinthwt]

Thank you Randy. I will move on to that one.

[scotth89]

It's a vacuum line most likely. When I put my 2002 F250 in 4x4 the a/c will blow through the defrost for a few minutes then go back to blowing through the vents. Good luck.

[hellbndr23]

Something in your truck doesnt suk. correctly at least.

[Sparkles]

Are you in 4wd low mine wouldn't come out of low unless I was in neutral. Took me two hours to figure it out one day. Thought it was going to be a long slow drive home.

[BETTERLUCKYTHANGOOD]

You have a vaccum control valve on the right front fender behind the battery. I had to replace that on a customers truck last week cause he was loosing vaccum going into 4x4 and his fents would change on him. The hubs are spring loaded to go out of 4wd but you still have a shift solenoid on the axle that could be hanging up.