jake04f150

ok so I was installing my dual battery tray and behind the stock tray there was a plastic container type box with a vacuum line running to it and on the fire wall there is some type of sensor with 2 other vacuum lines running to it well I unplugged the line that goes to the box and no problems so I just stuck a small bolt in the line to block it off. then I removed the two going into the sensor and air leaked out of it for about ten seconds ok didn't think nothing of it I hooked them back up finished the install and went to drive it and when ever I get on the gas it sound like the front end is trying to engage so i figure it was the vacuum actuator for the front end and that plastic contain must have been important so I came home reinstalled the box and took it for a ride and its still doing it so I put it in 4 hi and it doesn't do it so now I'm sure that it is the actuator but it is still doing it with all the vacuum stuff hooked back up. so I don't know what to do from here. any ideas???
Thanks

rrogers1221

you definately caused a vacuum leak somewhere,the box behind the battery is a resevoir for the system and is essential for it to work.
https://www.f150forum.com/f4/4x4-tro...g-guide-39789/

this should help you figure it out

HiOffcr

Definately sounds like you damaged either the IWE solenoid or the vacuum line some how.

60DRB

I doubt you caused any actual damage by disconnecting the vacuum line. You will need to reconnect it if you want your 4x4 to operate correctly though. Here's another trouble shooting guide to review.


http://www.ford-trucks.com/forums/836438-everything-you-wanted-to-know-about-the-iwe-system-and-then-some.html

rawhp88

jake, i just had the exact same problem that you describe. And like you said, when its in 4wd the sound goes away. Mine did as well but 4wd wasnt really there. its would make a loud clunk when there was resistance to the front wheels. I did alot of damage to the bearings and the front hubs. And a week later when i got it back still made the same sound a mile down the road... well 4hrs. later back at the garage we ended up blowing all the air lines out. it works perfect now. we just took compressed air and un hooked the vac lines at the hubs and blew up and down about 15 times. a ton of crud came out. hope this helps

jake04f150

I just bought a vacuum tester and tested the system every line was in the green so now I'm gonna go try this^^^^^ and see if thats it I hope it is thanks guys

jake04f150

ok so i tested every line from the intake to the hub and they all are reading the same 16 in hg what ever that means but this was all at idle so when i was doing the top line that goes into the seloniod i had my wife rev the engine and as the rpms went up the vacuum went down is that what is supposed to happen?

60DRB

I know the thread I posted for trouble-shooting is very long, but did you go through all the testing recommendations? I have several posts in the thread as I went though the repairs on my truck.

Did you check if the IWEs themselves are holding vacuum? One of mine was bad, the seals were shot. There are two lines comming from the IWE. The larger one is for vacuum (use that one to check if the IWE is holding pressure/not leaking down) and the smaller is a vent line.

An intermittant fault with the old style solenoid is a very common cause of eventual IWE failures. Many people just replace the solenoid with the newer covered design THEN start the trouble-shooting. I followed the guide I posted and still had to replace the solenoid at the end of it all.

jake04f150

does any one have a part number for the actuator or is it a dealer only part and how much did it cost

jake04f150

ok I just ordered my iwe solenoid from my dealer it was $23.00 and they will have it today at 2 I hope thats what the problem is