Another 4X4 question
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Another 4X4 question
I have the EFOF I decided to check it out and when I turn my switch to 4X4 my transfer case engages and my light comes on. I had my heater on and was on high and then it went to defrost and stayed that way for about 30 seconds and then went back to heater. I put the truck in neutral set the parking brake and got under my truck and tried to spin the front drive shaft and could not so I know my hubs are locking in. I even was under the truck and had someone to shift my 4X4 on and the drive shaft locked up as soon as the switch was turned so I know it is working. My heater would stay blowing on high after it came back from defrost so I don't think I have a vacuum leak but I just wonder if I have a weak pump? I have tried shifting my 4X4 several time and it always dose the same thing, after about 30 seconds it would default to defrost then 30 seconds back to heater.
Postmaster
Joined: Jan 2009
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From: Glen Rose,Texas
Ford put some very cheezy vacuum hoses on these trucks.Check the hoses from the vac pump to the hubs.I bet you have a vac leak.Could be the solonoid as well.I had to change mine on my 02....God luck to ya
Hook it, I'll pull it.
Joined: May 2007
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From: Grand Lake, La.
When you put the switch in 4x4 it sends power to the motor on the transfer case to shift. It also sends a signal to the solenoid to start vacuum to lock the hubs. Just because you can't turn the front drive shaft by hand, don't mean the hubs are locked. It means the transfer case is engaged. Sounds like the guys have you on the right path with there being a leak somewhere.
Of the next Riffraff East
Joined: Oct 2004
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From: Concord NC
You could always jack the front wheels off the ground, engage your ESOF and see if you can turn the wheels. At least you will know if your hubs are engaging. The defrost thing still makes me think you got a small leak somewhere.
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From: Az
Easier than filling up your fuel tank.
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I am confussed, if I have a vacumm leak wouldn't my defroster stay on?
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Fleet Mechanic
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From: Fleetwood, PA
i have the same exact thing. i noticed that when i lock my hubs in and put the 4x4 on it works fine and the ac wont blow off different ways. try that. i am going to redo the vacuum lines this weekend.
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From: Fort Campbell, KY
Nope. IIRC it doesn't maintain vacuum to the hubs, it just sends a command for xx seconds to activate the hubs. If your HVAC is defaulting to defrost, you've got a leak
. Remember, you have a vacuum accumulator too, that has a big reservoir. That big oval thing behind the passenger side battery is a tank filled with vacuum (is that possible
), so that means when you shift to 4x4 your emptying that entire accumulator. I'd say a pretty BIG leak.
. Remember, you have a vacuum accumulator too, that has a big reservoir. That big oval thing behind the passenger side battery is a tank filled with vacuum (is that possible), so that means when you shift to 4x4 your emptying that entire accumulator. I'd say a pretty BIG leak.
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Nope. IIRC it doesn't maintain vacuum to the hubs, it just sends a command for xx seconds to activate the hubs. If your HVAC is defaulting to defrost, you've got a leak. Remember, you have a vacuum accumulator too, that has a big reservoir. That big oval thing behind the passenger side battery is a tank filled with vacuum (is that possible), so that means when you shift to 4x4 your emptying that entire accumulator. I'd say a pretty BIG leak.
. Remember, you have a vacuum accumulator too, that has a big reservoir. That big oval thing behind the passenger side battery is a tank filled with vacuum (is that possible), so that means when you shift to 4x4 your emptying that entire accumulator. I'd say a pretty BIG leak.
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From: Fort Campbell, KY
Hmmmmmmmmmmmmm After the defroster comes on for about 30 seconds it will go back to heater and stay at heater, I left it in 4X4 4 about an hour and the heater stayed on. When you shift to 4X4 vacuum locks the hubs, what keeps the hubs locked in and what unlocks the hubs when you go back to 2X4? Trying to understand how this thing works.
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I understand what activates the hubs but inside the hub when the vacuum dose it's magic, in other words how do the hubs work when I turn the switch. If vacuum is applied to the hubs to engage them then there would be vacuum to the hubs untill I put it back into 2 wheel drive, am I correct?
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From: Fort Campbell, KY
I understand what activates the hubs but inside the hub when the vacuum dose it's magic, in other words how do the hubs work when I turn the switch. If vacuum is applied to the hubs to engage them then there would be vacuum to the hubs untill I put it back into 2 wheel drive, am I correct?
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Well I have discovered that my hubs are not locking in as yesterday we were having a pretty good amount of snow and the roads were covered. So I manualy locked in my hubs and turned the switch to 4X4 and the light came on and I heard the transfer case engage. Pulled out the drive and got stuck, friend said front wheels were not spinning sooooooooooooooooo now I was going to replace my hubs with Warn #11690 but Warn says they will not fit dual wheel application, I wonder why they won't.