So I tore into my ESOF tonight and this is what I found

onephinesuperduty · #1 (**permalink**) 09-20-2009, 10:13 PM

2001 F250 5.4 V8 4X4. ESOF hasnt worked right since I bought it. Switch works, lights on dash work properly, I can feel and hear the transfer case working underneath me, but the hubs wont lock in auto, switch em to manual no problem at all. I took the connector off and checked the 3 pins in the pvh solenoid, center pin only has power from the harness. My assumption is that something must be malfunctioning in the solenoid itself. Going to check into a new one tomorrow. Havent checked into any vacuum line issues yet, however drivers side going into hub was broken, now replaced. Can anyone shed some light on if im headed in the right direction? Thanks in advance!

dchamberlain · #2 (**permalink**) 09-20-2009, 10:50 PM

Voltage is on center pin (2) when the key is in run. Pin 1 is grounded by the 4x4 control module to lock the hubs. Pin 3 is grounded to unlock the hubs. You'll need a continuity tester to check for continuity between pins 1 or 3 and ground at the proper time.

Remember that the solenoid is commanded to apply full vacuum for a few moments to lock the hubs, and lesser vacuum is supplied for a few moments to unlock the hubs.

You may have already fixed the problem by fixing the vacuum lines. I'd check that before I did anything else.

onephinesuperduty · #3 (**permalink**) 09-20-2009, 11:04 PM

Checked to make sure they were still inoperable, indeed they are, Ill pick up a continuity tester tomorrow at work

EXv10 · #4 (**permalink**) 09-21-2009, 12:42 AM

You should have a pressure tester and need to clean/grease hubs before you proceed. Unless they have been done.

EXv10 · #5 (**permalink**) 09-21-2009, 12:46 AM

Quote:

Originally Posted by dchamberlain

Voltage is on center pin (2) when the key is in run. Pin 1 is grounded by the 4x4 control module to lock the hubs. Pin 3 is grounded to unlock the hubs. You'll need a continuity tester to check for continuity between pins 1 or 3 and ground at the proper time.

Remember that the solenoid is commanded to apply full vacuum for a few moments to lock the hubs, and lesser vacuum is supplied for a few moments to unlock the hubs.

You may have already fixed the problem by fixing the vacuum lines. I'd check that before I did anything else.

Could I manually bypass the module to check the system by grounding 1 and 3 out?

dchamberlain · #6 (**permalink**) 09-21-2009, 09:34 AM

Quote:

Originally Posted by EXv10

Could I manually bypass the module to check the system by grounding 1 and 3 out?

I don't see why not. I'd disconnect the wiring harness, so there isn't any chance of accidentally putting a voltage to a computer where it doesn't belong. Just put a jumper from pin on of the solenoid to the battery and a jumper from pin 1 or 3 to ground and see if the solenoid opens.

onephinesuperduty · #7 (**permalink**) 09-23-2009, 07:28 PM

I installed the new PVH Solenoid for the vacuum tonight, still no go. Took for a test drive. Transfer case works because if i shift it into 4 LOW it limits my speeds. All lights on dash work for 4x4 as well. System works as it should If i get out and lock the hubs into LOCK. Id just like for them to work on auto. Im not aware that it has any vacuum leaks because the HVAC system acts as it should, it doesnt revert to defrost. Any suggestions on where I should go at this point?

EXv10 · #8 (**permalink**) 09-23-2009, 07:34 PM

Did you clean/grease the hubs? Not hard to do ..........check seals in there too. (2 more seals further in)

BBQ · #9 (**permalink**) 09-23-2009, 08:28 PM

We just finished replacing the ball joint on my similar 01 F250/5.4 CC 4WD and replaced the seals as mentioned above. ESOF worked like a charm when we were done.

The main seal a hell of a fit, the dust seal is easy, and the o-ring was a breeze.

Used the FTE Ball Joint thread for guidance http://www.ford-trucks.com/forums/35...ll-joints.html

SpringerPop · #10 (**permalink**) 09-23-2009, 09:16 PM

Quote:

Originally Posted by onephinesuperduty

Any suggestions on where I should go at this point?

Try this?
http://www.guzzle7pt3.com/allube.php

Pop

onephinesuperduty · #11 (**permalink**) 09-24-2009, 09:48 AM

Thanks for the useful replies. Im taking the truck to the Carolinas on vacation for 10 days. However, I ordered the seal kit today so It will be waiting for me when I arrive home. Ill throw it in and let you all know how it goes!

onephinesuperduty · #12 (**permalink**) 10-06-2009, 04:51 PM

Well I got the outer seal kit from ford and replaced both big o rings on the outer lip of the hubs and used guzzles lubrication guide to no avail. Hubs still wont autolock? Time for new ones?

EXv10 · #13 (**permalink**) 10-06-2009, 10:43 PM

Pressure test the lines if you haven't. There should be pressure for 15+- seconds to engage and disengage.

SpringerPop · #14 (**permalink**) 10-06-2009, 11:04 PM

Vacuum, not pressure, pulls on the diaphragms that act on the engage/disengage mechanism.

That mechanism is a little like a ball-point-pen's "click on, click off" design.

It's apparent how it works if you take one apart to service it.

Pop

EXv10 · #15 (**permalink**) 10-06-2009, 11:07 PM

Quote:

Originally Posted by SpringerPop

Vacuum, not pressure, pulls on the diaphragms that act on the engage/disengage mechanism.

That mechanism is a little like a ball-point-pen's "click on, click off" design.

It's apparent how it works if you take one apart to service it.

Pop

That's what I meant. I knew I would be wrong sooner or later.