Question about the ESOF system

[DirtyJerseyStroker]

I've been having a problem with the ESOF 4x4 system. I was getting the defrosters coming on when the 4x4 was turned on which indicated a vacuum leak in the system. I said to hell with finding the leak and replace all the 4x4 lines with new ones. Now that i did that the there are no vacuum leaks in the system but i am only getting 10 inches of vacuum at the hub line when switched on and nothing when i turn it off. Could it be a bad vacuum pump or a bad solenoid switch? I thought i could be the vacuum tank as well. I just recently ordered new ESOF hub locks so i can manually turn the hubs into the locked position for the winter. My old ones were completely frozen! If it may be the tank, is there a place where i can get one. I have found the ESOF Solenoid and the pump, but can not find the vacuum tank.

Thanks in advance!

 

[RescueF250]

Sunrise Ford is a vendor here, probably can help you out on that part. Did you replace the pump ?

 

[DirtyJerseyStroker]

Not yet. Im going to start there this spring. I will just lock the hubs manually this winter!

Thanks for the reply

 

[DSTRYER]

I had never heard of problems with this...is it common?

 

[mcdaniel1991]

Not to take away from ur question but my defroster has always came on when I switch it into 4x4 at one point I tried to find the leak but can't and I have kinda just accepted it is it ok to leave it like this?

 

[CCRICE]

I bought the stainless kit from deiselsite, good upgrade for like 80-90 bucks. You could have a leaking hub though.


Sent from my iPhone using Tapatalk

 

[Jarrod B]

i unpluged the solenoid and that solved the issue on my last truck. the auto hubs never worked anyway and ended up with warns. this current truck works atm.

 

[DirtyJerseyStroker]

Not to take away from ur question but my defroster has always came on when I switch it into 4x4 at one point I tried to find the leak but can't and I have kinda just accepted it is it ok to leave it like this?

One of the things you can do is cap the solenoid vacuum lines and just turn them manually. I really want to get the automatics working again, but if its a leaking hub, ill just let it go until i need to replace wheel bearings.

As for the leaking hub, i hooked my vacuum gauge up before the Y connector and what is happening is i get 10 in of vac when i turn it on and it bleeds away quickly. When i switch 4x4 off, it doesn't even show vacuum.

 

[G Racing]

Dynatrc conversion for the win

 

[DSTRYER]

is it only with the auto lockers?

 

[Lassie]

The pulse vaccuum solenoid is the source of the leak very often. If you're getting vaccuum less then 15 in coming to the hub, or bleeding down, that's my bet.

Turn the key on (engine not running) and the vaccuum pump should run. The pump has a line connected to the vaccuum canister. The canister has another line leading out. Disconnect it and plug in vaccuum gauge. When key is on, the pump will run and pull 15 in of vaccuum in the tank, and it should hold. If it does, your pump and vaccuum tank are good.

Next, test the output line from the solenoid. If vaccuum leaks there, its your problem.

 

[DirtyJerseyStroker]

Thanks Lassie, Ill try that! We will see what happens!

 

[Lassie]

I went through all of this recently. I ended up having a leak on driver side hub and my pvh solenoid. If you get a vacuum gauge, its a pretty simple system to troubleshoot, and pretty cheap to fix, unless you find a bad unit bearing.

And that's the problem I see with changing over to manual locking hubs to get away from this.........the opening in the unit bearing will still be there and if the knuckle seal was bad, it will only get worse!! The seal had worn so badly on mine, that dirt was getting into the spindle bearings. I went through two unit bearings in less than a year due to this.

Unit bearing = about $300
Knuckle Seal and dust seal = $40

There's nothing wrong with going to manual lockers, but you need to maintain the knuckle seal, and it seems to be the most common of the three ESOF seals to fail.

 

[DirtyJerseyStroker]

Yup it is the solenoid. The pump and tank both get to 35 in of vac and hold. So ill order the solenoid. Hopefully this is it and not the seal. I may or may not switch to manual lockers. Can i still keep the truck the way it is and just turn the locks manually on the hubs for the time being?

 

[mcdaniel1991]

Ok I'm confused now? I just read the esof Manuel and if I understood it right my dash switch should not work if my hubs are set to lock that I should be in 4x4 anytime my hubs are locked ? That is not the case though my hubs are set to Manuel but I can turn the 4x4 on or off or into low via the dash switch ? Am I not understanding something ?

 

[DirtyJerseyStroker]

Ok I'm confused now? I just read the esof Manuel and if I understood it right my dash switch should not work if my hubs are set to lock that I should be in 4x4 anytime my hubs are locked ? That is not the case though my hubs are set to Manuel but I can turn the 4x4 on or off or into low via the dash switch ? Am I not understanding something ?

If that was true then your hubs will be locked but your transfer case will be disengaged, so manually locking the hubs is useless. If the system faults where you have a vacuum leak, you are supposed to be able to switch the transfer case into 4X4 via the ESOF switch then manually lock your hubs!

 

[Lassie]

The dash switch only controls the transfer case solenoid and the pvh solenoid. The pvh sol stays on for approximately 30 sec when 4x4 is switched on. Stays on approximately 10 sec when switched off. The indication on your gauge cluster ONLY indicates the transfer case solenoid.

If your hubs stay locked in manual, your wheels will spin the axle shafts back to the front chunk, but the transfer case will not be driving them.....therefore your engine will not be driving them.

The vaccuum system is not monitored by any device. You have to watch the axle shafts to see if the ESOF system is working. You can also feel the difference when it engages.

 

[mcdaniel1991]

Ok I put them back in auto so now the wheels should spin freely as if there were no 4x4 correct? The 4x4 still works when turn it on but I stil get the defroster

 

[Lassie]

Yes, but they may be stuck engaged also. Auto hubs need vaccuum to engage and disengage....thats what the pulse from the pvh solenoid does. If your air switches to defrost when in 4 x 4, then your hubs are probably staying engaged. Thats where my issue started.

To check, jack up one side of front end. With truck in 2wd, spin tire back and forth. If axle spins, you have a stuck hub. This causes unecessary wear to the spindle bearing inside the unit bearing.

The only way to disengage mine was to pull the locking hub until it popped out, and then reinstall.

Find the leak first. With the air on, switch into 4x4. The air will switch to defrost just for the amount of time of the pulse to the hubs. (about 30 sec) Same thing releasing 4x4. If this happens, you DEFINITELY have a vaccuum leak that is located in the pvh solenoid housing or beyond.

The problem with a busted ESOF system and leaving it that way, is that you have no way to freespin. If you use the manual lock, even when you roll back to auto, it wont unlock. You will always be spinning the front axles...even at 80 mph!

 

[Lassie]

If you dont want to lift the truck, have someone drive straight at you (slowly) and watch the front axle shafts in 2wd and 4wd. I would wager that several people will find out that they are spinning at least one front axle shaft all of the time.

P.S. I would warn against having your wife be the driver if you've been married for any length of time.