I recenlty purchased my 2003 F 350. The ESOF does not work. I reviewed the post on how to fix your ESOF 4x4. From watching that video, I found the problem. I have a vaccum leak on my drivers side hub. I get zero vaccum when I put my vaccum pump on the drivers hub. I blocked off the vaccum line to the hub and the pump will eventually stop, it is constantly running if I hook the line up to the hub and run my 4x4....4x4 does not engage by push button. My 4x4 will work if I lock the hubs manually.

I purchased an O ring kit for my hub. The kit came with 2 rubber O rings and a clamp. When I removed the locking section of the hub, there was only one rubber O ring. Am I missing something, like a second O ring? Or is a new hub in order?

Thanks for the info

 

Its more than likely the hub seal thats bad causing your vaccum leak. It presses on to your axle shaft and seals the steering knuckle. Its a big blue disc looking seal. Youll have an oring on the back side of your hub assy. Those are what seals up the knuckle to keep it under vaccum.

 

Is there a how to do this repair anywhere? I looked on Youtube and found little to nothing

 

A Haynes or Chilton repair manual would help you out. I can give you Mitchell info but its several pages long. Youll pull wheel, caliper, rotor, disconnect abs harness from brake hoses and frame connector. Take the 4 hub bolts out, they screw in from the back of the steering knuckle. Then use a long pry bar between the axle shaft and axle tube and pry the axle and hub assy out. Then you can remove the axle shaft from the hub on a bench. Or before you pry the assy out, remove the hub lockout then remove the axle shaft retaining clip and washers - keep washers in order. Then pry the *** out and remove the hub from the axle shaft as it slides out of the knuckle. Replace the oring on the knuckle side of the hub, remove the seal from the axle. Install the new seal onto the axle (there is a special tool) Then install the axle back into the housing and seat the seal into the knuckle with the special tool.