Is the solenoid located near the pump? Can I check if the solenoid is working somehow (perhaps applying +12v to a lead).

Thanks,
Beefey

 

Click on the thread link I put in post #6.

 

Don't be fooled by the fact that you are able to lock your hubs manually ! These trucks have both auto/manual hubs in them from the factory. You still have a dial on the hub itself.........Is he sure they are only manuall hubs and not auto with a manuall option ???????

 

Russ, that's a good point, I'll have to check to see if there is a vac line running into the hubs (this would be indicative of your suggestion correct?) To clarify, I have manual locks on the physical hub and a "dial" in the cab (2wd, 4x4H, 4x4L).

I can still switch to 4x4 without any problems, I havent tried it yet but solely manual locks or the switch so I can't be sure.

Thanks,
Beefey

 

Thats correct. The auto hubs still have the manual "dial" on the front of them. YES You should be able to see the vacuum lines if you have auto's. It will be a black rubber hose that comes from a steel line as it enters the wheel well. The hose will go down with the brake line and go into the big knuckle on the hub assembly !

Make sense ???

Have you read the link that Robin gave you above ?????? That im sure tells you all about your hubs !

 

It seems like that is the worst of both worlds then... having to rely on vacuum for the auto feature yet still having to physically lock them.

I checked there is a vac line running to the hub, it feels rather soft. Should it be firm like a brake line? 4 cans of PB blaster and a torch may be able to bust this free...

Is the general opinion then that the hub leak wouldn't matter because it only runs burst for like 30 seconds when switching? The solenoid is then enemy #1?

Thanks,
Beefey

 

A leak in that hose to the hub is very common and will make the auto hub not work.. so yes..... it is an important piece of the pie.

 

I had the same defroster issue but my auto hubs still worked. I capped off the lines and used a short jumper hose at the pump. Defrosters work as well as all the other settings. I did however have to old-school lock the hubs. Now I run the Dynatrac Free Spin kit so I have to lock - unlock anyway.


You can see the two bolts I used to cap off the lines and just below that is the short hose I used to reroute. It has some dielectric grease on it from the last time I had the bat cable off.



Here is a shot of the Dynatrac hub. These are built for sledge hammer mechanics like me!

 

those look like the WARN premium hubs that I put in mine !

 

Yup. Came as part of the Dynatrac kit.

 

Lots of guys switch to a good manual hub. It's cheaper than buying new OEM hubs and they are much better quality. I am old and don't really want to get out every time I want to shift, plus I am not a real fan of leaving them locked and running with the front shafts spinning. Regardless of any (or no) mechanical implications, that's my personal preference and, as I mentioned, I'm not young so I don't change my mind easily!

Regardless if you have any plumbing in place for the ESOF, your truck came with it (switch on the dash) so you are in the same pickle as all of the rest of of ESOF guys. If you don't care about manually locking the hubs, disconnect the line BEFORE the solenoid and plug it, that way you won't have ANY problems with a failure in the hub (vacuum) portion of the ESOF system. Mine just started to go to defrost during the shift AGAIN this weekend when I was off-roading and I'm about to drive it off a cliff!

If it's the lines, it's pretty cheap to fix. If it's in the hub cavity, it can go either way $$$-wise, but it's a pain to pull apart to find.

I know that www.dieselsite.com sells steel braided lines for the ESOF that goes through the wheel well to the knuckle (the most common failure point). The rubber line is only sold as OEM by Ford with the entire brake line bracket too, so it's not cheap ($70 or so if I remember). I don't remember the inside diameter, but most go to an auto parts store and buy some vacuum line to replace their old line with and it's only a few bucks.

Just my .02.

 

I may not completely understand this system but here goes...

If I simply plug the vac lines to the hubs I still have 4x4 I just need to lock them manually (like I already do)? So that's the route I'm going to take. I'm a young guy with an open mind =)

So first off I'm gonna plug the vac lines to the hubs, if that works steller if not I'll move onto diagnosing the vac pump itself. The solenoid is no factor if the lines from the vac pump are plugged off right?

Tell me if this sounds good.

Thanks,
Beefey

 

bump, thanks

 

If the HVAC doesn't default to defrost with the vac lines plugged then one of the hubs has a vac leak.

With the hub vac lines plugged you will need to turn the hubs clockwise to lock. Just remember "Clock-Lock".

 

I've been through this several times and my problem always originated with the pump itself. It should cycle intermittently and is obvious to the touch if it's on or not. My recommended test method is to whack it with a Mag-Lite or something similar. More often than not that would get mine going again. At one time I disassembled the pump on a hunch that the internal switch wasn't aligned correctly. Turned out that's exactly what it was and I was able to slightly bend one of the contacts and it worked perfectly for about 6 years. It has quit on me again and appears to be dead, which is why I'm searching these posts.

Anyway, check your pump before you look for leaks in every possible inch of your vacuum lines.