4 Wheel Drive Question
Postmaster
Joined: Jul 2006
Posts: 3,754
Likes: 1
From: Indianapolis
Yeah, you're ESOF is not working- it's a stupid design meant for lazy people.... More than likely you have a cracked vacuum line somewhere. There is a vacuum pump on the right inside fenderwell behind the light. If that was out, your A/C system would be stuck on defrost, so if that's notthe case then you gotta justfollow your vacuum lines and look for the problem. ALSO, if your lines are ok, then the big a$$ yellow o-rings in the hubs could be leaking too. Do a search for GUZZLES mod page, shows you how to tear the hubs apart and rebuild them leak free.
Postmaster
Joined: Jul 2006
Posts: 3,754
Likes: 1
From: Indianapolis
I just had both my hubs replaced at the stealership because I just don't have the time to do it myself. Well, for the first time since I've had the truck (about 70k miles) the damn things do lock. HOWEVER, now they stay locked. The T case will disengage, but I gotta mess with the darn hubs to get them free wheeling again.... I can't win
Mountain Pass
Joined: Oct 2005
Posts: 191
Likes: 0
From: NH
I went to a junkyard and got a second vaccuum pump from a volvo. Between both and new hub seals and vac lines....it works fine. But they need to be cleaned and relubed twice a year to keep them working. I also dont go a week w/o engaging the 4wd to keep things from freezing up. I dont mean in the winter...I mean in the summer when you normally may go 2 mos w/o needing 4wd.
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Posting Guru
Joined: Jul 2006
Posts: 1,720
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I have 144000 miles on my Ex 7.3 4wd and the ESOF has worked great. I had to replace the vac. lines to the hubs at 100000 miles. I suspected the o ring failure when they would not energize last month so I pulled them to check and found the wheel bearing bad. Whew fortunately the ESOF quit or I might not have found the bearing. Now all on that side is new. The esof is basically a simple vacuum line from the storage tank to the T then to the wheels. Pretty simple system. But then I don't like getting out in the rain/cold to manually switch the hubs.
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New User
Joined: Sep 2008
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Sounds good. Thanks for the information!
That pump is not running. I was under the hood a few weeks ago with the ignition switch on, and remember hearing it pumping. but it isnt working now. I have a 2002 F-250 with 208k miles on it. So little things are starting to wear out here and there. Thanks again
That pump is not running. I was under the hood a few weeks ago with the ignition switch on, and remember hearing it pumping. but it isnt working now. I have a 2002 F-250 with 208k miles on it. So little things are starting to wear out here and there. Thanks again
Postmaster
Joined: Jul 2006
Posts: 3,754
Likes: 1
From: Indianapolis
Check your fuses- it's #13 on the diagram IIRC, the 3rd one up on the right hand side, I think it's a 10 amp fuse. You'll also notice that the A/C will only blow on the defroster- that's the factory default incase your vac system takes a chit.
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