tomb1269

I thought I would give everyone a cheap fix for the IWE Vaccum Switch water intrustion problem. If you are not aware Ford re-designed the Switch Mount assembly to include a hood (which makes it a PITA to disconnect the vacuum or electrical lines with out un-bolting the unit from the firewall). The problem lies in the fact that the switch is also the vent for the vacuum line running to the IWEs and it is mounted directly underneath a high water location. It sits behind the battery right under the point in which the cowl stops. So therefore any water run-off can come down on top of it, and if you switching in to 4x4 mode at the time it will suck water in to the IWE side vacuum line as the cap on the top of the switch is actually the vent to release the vaccum pressure at the IWEs.

Solution: Spend $25 at Advanced Auto or similar store (Ford will actully sell you the old style/non-hooded version) OR... Make a Cheap Hood Yourself.
1. Dismount the switch.
2. Take an empty windshield washer bottle (or like plastic). Cut out a piece that is as big as the mounting bracket in width and with enough length to cover the top of the switch. (i actually trimmed the length after I mounted the switch).
3. Punch holes that line up with the switch mounts bolt holes.
4. Slide the plastic on the firewall studs first, and then mount the switch back like it was.
5. Bend or crease the plastic and trim to fit as you see best.

I am new here, but I had not seen any posting providing the info and solution for this problem, so I thought I would start one and maybe save some one out there the cost of the switch and if done early enough, maybe the cost of replacing IWEs, as mositure/water contamination seems to be the biggest killer of our IWEs.

scvfd02

Excellent idea. I wish I had thougth of that. My solenoid works fine, except for realeasing the vacuum.

I had the grinding IWE problems while driving down the road and diagnosed that both of the check valves went bad, and replaced those. Every now and then I can get the front hubs to lock correctly, but most of the time, they won't, since the vacuum won't release.

I have a new solenoid coming (found online for around 19.00), with the new bracket and the hood, so hopefully it will fix my problem. But it seems the engineers overlooked be able to disconnect the vac lines and the wire harness easily... Oh well, we can;t always have our cake and eat it too.

theduke308

I put an aluminum foil blanket over mine to make water shed off it

tomb1269

Are you sure you did not reverse the vaccum lines a the solenoid as we did? I was having engagement problems due to the engine vacuum side/line being connected to the vent cap and the EWI vacuum line / side to the stopper. So therefore, when I thru the switch the vacuum to the hubs was not being released, it was just sealing the line and the engine vacuum was sucking in air thru the vent cap but not enough to cause engine runnig problems.

scvfd02

At first, that's what I thought I had done after I replaced the check valves. With the way the two vac lines connect on my solenoid, you cannot reverse them without some effort, as the rubber molded piece that hold the lines together is shaped to match the offset of the ports on the solenoid. I still have excellent vacuum at the IWEs.

Good thought though, it seems your problem solving process is similar to mine.

jamie930

The piston part of the solenoid will stick as there are rubber ends on the piston. If you take the cap off the solenoid you could stick a small allen wrench in the hole and check the depth that wrench goes with 4hi on and off if its the same. Give a push when 4HI is on

conq

Where are the check valves? Im having an issue with noise from hubs during 4wd only, could be not releasing vaccuum fully now that i think of it.

tomb1269

Most likely your problem is with the HUB or IWE (Independent Wheel Ends). As you know they are vaccum actuated and when you have a small leak or contamination (Vacuum switch on firewall will allow water to be sucked in to IWE side vacuum line) it cause the units to only partially disengage which causes a grinding sound.

2nd150

How about a pic or two??