Good place to start. I'll try that. Thanks.

Any idea where I could get a diagram for this system?

 

i dont know if a haynes manual would have one in it or not

 

OK - On the way out to NW Nebraska (1,800 miles - each way), I kept hearing what I thought was break pad chatter. I blew it off - only thinking I would have to do a break job when I got home. Nedless to say, on the way home, it got worse and I determined that it was an IWE problem. I have read this thread before.

Got it home and went to work. I found a bad seal on the drivers side actuator. Did a bubble test and determined that it was a minor leak. Cleaned it up and put the silicone band aid to it. I pulled 25 in Hg and it held for four hours. While under the vaccum test I broke down the system, cleaned the lines, and tested all of the above. Then I broke down the passenger side hub and actuator (that is the side that was making all of the racket). The actuator gear was chewed up pretty good. It is Sunday so I just cleaned up the splines on the gear, flipped it 180 degrees and put everything back together.

Everything tested out fine, Vaccum is holding at 22 in. Hg. Road test is a success. (By the way, I cleaned the check valves with water and soaked them in armour all and they are now working fine - they were full of trash) Thanks XJ, I reckon you saved me a lot of time and headache.

 

Ok. Here's the wiring diagrams for the IWE

 

is this system the samefor a 2003 truck

 

Thanks so much for spending so much of your time sharing your extensive knowledge.

I am working on my mother-in-laws 2003 Expedition. The passenger side hub is making that ever so distinct ratcheting / ginding sound, when in 2WD. I pulled the vacuum line off the hub actuator and there is NO vacuum present. Just for good measure, I pulled the driver side line of the actuator and there is definitely vaucuum on the driver-side hub. I was wondering where the "TEE" occurs in the vacuum lines that separates the passenger / driver side and or I was wondering if one check valve out of the two you mention is designated to run one side or the other?

Thanks much,

dean.

 

Got it. No need to answer my previous post.

Thanks.

 

Update: Anyone experiencing the power to the solenoid being intermittent should consider replacing the alternator.

 

Really? Good to know. I know these trucks do some weird things when the battery or alternator go.

 

Yep. Replaced my hubs (one was actually bad) and the problem remained. Replaced the solenoid and the problem remained. Traced the schematic and found no problems. Thought it might be the PCM (glad it wasn't) but on a hunch I checked the output on the alt. Turns out the regulator was going out and the voltage was creeping up to 17+ volts occationally. When it did, it "fooled" the PCM into thinking the switch was in a position with less resistance. Bad design in my opinion (having everything on a single wire through the switch... see schematic). Anyway, replaced the alt (which needed to happen anyway apparently) and problem solved.
BL: Everything I replaced either needed to be replaced anyway or it is something I should keep a spare on hand (actuator/solenoid).
So, another guy smart on a dumb system.

 

I think I posted here many pages back, the Haynes manual is utterly useless for any 4x4 repair/trouble shooting purposes.

TN 150 posted a very good cut-away digram of the IWEs at the end of his thread recently. I can't get the picture to attach for some reason...

http://www.f150online.com/forums/200...replacing.html

 

xjcamaro,

Could you give me a hand?

https://www.ford-trucks.com/forums/1...questions.html

This is what I got so far but I don't know how far I am off.

 

Is this on a 5.4? Mine was a 4.6 and i dont have all those extra lines all connected like you are describing, i have one line coming off the TB dedicated directly for the IWE system. As far as the check valves and the direction. Think of it this way, when you get the new ones suck on each end, whichever end you can easily suck air through is the end that will go on the line coming off the engine, then the other end will go on the line going to the IWEs, you want the engine to be able to suck air though the check valve, but when you loose vacuum coming from the engine because of high RPM or load you want the valve to "check" or close and hold that higher vacuum on the IWE side of the valve. If you replace the easy stuff and still get a grinding noise, you need to get a vacuum guage and test the IWE's themself, because if you have a leaky seal on the IWE itself it doesnt matter how many solenoids or check valves you throw at it, it always going to leak.

 

Oh, and i have yet to find a vacuum diagram

 

Thanks for the help. Yes it is a 5.4L

I am also have issues with the HVAC system as I am only getting defrost instead of on the floor or out the vents. I know there is something else wrong with the entire thing.

On the IWE solenoid. Is it connected the way I am showing? Top port to the vac source and bottom out to the IWE's?

I have two vacuum lines that appear to be going down to the left and right IWE's but I might be missing something else I am unaware of. I cannot locate the IWE vent lines from the top so I guess I will pop the wheel off and take a look at it from the bottom.

Probably going to go find a used Navigator and try to figure out the routing of the vacuum lines that way.