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Old Jul 27, 2008 | 10:18 PM
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4X4 problem

I have a serious problem considering half of my income is hunting and fishing. First off i will let you know i have automatic hubs.When i put the switch into 4X4 it takes forever for the light to kick in and when it does it doesnt work hardley ever if any! Thats not the wierd thing when i do this it sometimes switches my air over to defrost for some reason......ya go figure. So confused. Please help me!
 
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Old Jul 27, 2008 | 10:24 PM
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You have a Vaccum leak for sure. The hubs share the same system, and it'll affect both if there's a problem.
 
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Old Jul 27, 2008 | 10:26 PM
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Thanks for the help, do you know how i could check that. because i dont have a clue about that stuff.
 
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Old Jul 27, 2008 | 10:30 PM
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Originally Posted by 7.3blacksmoke
Thanks for the help, do you know how i could check that. because i dont have a clue about that stuff.
I've only read about it on here, haven't had that problem yet myself.....do a quick search for 4x4 vaccum leak, or something along those lines.....that should get you pointed in the right direction!
 
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Old Jul 27, 2008 | 10:30 PM
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Yep, vacuum leak or the vacuum pump might have bit it. Someone will chime in with a good way to find vacuum leaks. I've always tried spraying carb cleaner, or for a 7.3, maybe WD-40 would be better. Follow the vacuum lines spraying the WD-40, and listen for the idle to change. There are other ways too, maybe someone will have a better one.
 
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Old Jul 27, 2008 | 10:41 PM
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check the vacumn hoses that go to your hubs...they are probably dry rotted and in very bad shape...just replace the hoses and you'll be ok
 
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Old Jul 28, 2008 | 05:13 PM
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I had the same problem. I just replaced all the orings in the hubs about a month ago and just last weekend I had the AC on and put in 4x4 and the AC went to the defrost. I used one of the vacuum checking/brake bleeding setups like you get from advance. It comes with different ends and all it is is a hand pump with a gauge(just sock the right end in the vacuum line and pump it up and see if the gauge moves). I found out I was loosing vacuum at the passengerside hub. Got the new yellow oring and hub orings from ford. Took the truck apart and replaced the yellow oring on the hub and cleaned up thw knuckle and hub where the oring rides. Put it back together and forgot to replace the oring on the hub and was still loosing vacuum. Luckily I looked on the bench and saw the new oring in the pack. I was about to loose what religion I had left after dealing with that dang snap ring on the axle. Replaced that oring and all is well. I know this was long but just figured I'd give the full run down of what I did. I hope this time it lasts more than a month!
 
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Old Jul 28, 2008 | 05:22 PM
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well i went out to look at things and i turned my ignition to the on position and then turned it to 4wd high and i listened to the vacuum pump and it ran fine (it sounded like to me). but i only had one question about it, there was a white teflon peice that had nothing hooked up to it and was blowing air. is that right or was there a hose once connected?
 
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Old Jul 28, 2008 | 05:31 PM
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I think I know what your talking about, thats right. Theres nothing hooked up there. The pump will run for so long then cut off when it builds enough vacuum. I guess that just the vent for the pump?
 
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Old Jul 28, 2008 | 05:32 PM
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From the front of the pump there is a line that goes to the vacuum canister. Another lines leaves the canister right next to it and "T's". One side of the T goes to the AC system, the other side goes to the 4WD Vac crtl valve. The hubs are fed form the ctrl valve. A lines leaves the valve and T's to each hub. There should not be anything unconnected that is blowing/sucking.
 
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Old Jul 28, 2008 | 05:40 PM
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From: Monroe VA
On my truck there is a piece like he is talking about that does not to hook to anything and hasnt since i bought the truck, that why I assume its just the vent for the pump. My guess is the problem will be either the vacuum line to the hubs or one of the orings in the hubs.
 
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Old Jul 28, 2008 | 05:49 PM
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thanks guys i will take a look and respond back, i need to get in gear hunting season is just around the corner.
 
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Old Jul 28, 2008 | 05:53 PM
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I hear ya! Some hunter I am, I havent hardly touched my bow in 6 months! Not good!!
 
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Old Jul 28, 2008 | 05:56 PM
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King, may well be such a feature, haven't noticed it, but seems there needs to be a vent for the pump somewhere.

7.3blacksmoke - After just missing dumping the rig in a culvert last year due to the ESOF not engaging, I figured what the heck, if I can't trust it, replace it. So I did. Bought a set of WARN manual hubs. Install takes about 10 minutes per side and you can find them on line for aorund $110 delviered...
 
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Old Jul 28, 2008 | 06:18 PM
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I replaced each of my wheel-well vacuum hoses with 22-1/2 inches of 3/16" (4.8mm) SAE 30R7 fuel hose each side. Secured the ends with a tie-wrap.

It should last a lot longer than OEM, and it fits perfectly.

Pop
 
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