Ok so I just went out and disconnected what I think is what you are talking about. I found a line coming from behind throttle body that connected to a smaller line that come from solenoid on firewall. Do I need to plug both of these? And what do I plug em with? One more question will the truck turn like it is in 4x4 with resistance or normal like in 2x and will it be ok to drive like this on highway say like 70mph?

 

Thats the right line.

If you left the check valve on the line coming off the intake i would just plug the open end of the check valve with a rubber vacuum cap if you have one. If not if you have a chunk of vacuum line that fits the open side of the check valve cut a short peice of it and put a screw in one end of the hose (a screw that is slightly bigger than the opening in the hose, this will plug it off) and then attach that to the open end of the check valve. get it?



I know this is sort of crude but it might help.

 

Thanks man you have helped me alot. So when you put new vacuum lines in did you put new check valves in also and how do you know where to put them? I guess in about the same location as existing ones? It would be easier to do like you said with vacuum hose from parts store and have extra so you can run to each actuator easily without having to somehow put back in same location as factory run hose.

 

Ya, i got new check valves from NAPA as well, they might not look the same as the ones that come out, they might have more ports, but just plug the ports you dont use, but they willl work the same. I also got a couple packs of assorted plugs and connectors (T and straight ones)

What i ended up doing was removing the original hoses by just cutting out all the old hose i could see cause it runs on top of the cross member under the engine and is hard to get to.

Good luck!

 

Yeah I've been looking at the hoses for last couple of days, just thinking to myself man I oughta just rip this crap out and put new in. Think I'm gonna wait til it warms up a little more before I tackle that and in the meantime I'll just plug this check valve and hope for no more grinding. Can I leave the connector on the hose that goes to the solenoid open or do I need to cap it off too? I promise last question for today LOL thanks.

 

You can leave it open, that hose is sort of "dead" in a sense that it does nothing when not connected. I would just tie it out of the way or something so it doesnt lay on the header or anything like that.

Try it out, i bet you dont get any grinding.

 

Hey XJ, with every turning up under front will the truck turn like its in 4x4 or 2x? And will it be ok to drive on highway 70mph+

 

No it will not turn like its in 4wd because the wheel are not "driving" they are being pushed.

 

XJC89 ...Haynes should've talked to YOU before publishing their manual on F150s!

When you re-routed/replaced your lines, did you just use rubber line, or did you use a mix of rubber and the hard lines like oem? I agree with your idea on running the [new] lines where they can be accessed/seen.

Q: (after repairs) Is there any way to know if the IWEs are actually disengaged when you're driving in 2wd? All I know is what they sound like when they are ALMOST disengaged-the grinding we all have heard while driving. ...the first time I heard that noise I thought the xmsn was about to explode!

 

XJ, quick question, I found a small cut in cv boot next to driver side actuator (the one making noise when vacuum lines connected) would this cause actuator to loose enough vacuum to try and engage? I put some black hi temp silicon on the cut hopefully will seal up.

p.s. After disconnecting vacuum lines had NO GRINDING NOISE!!!!!!!!!!!!
Just had little bit of grease sling out because cv boot had cut in it and was turning with vacuum disconnected.
Thanks again!!

 

Maybe i should call them up, i dont think there is any repair information in the haynes manual for the IWE, it just describes it but doesnt show you how to replace or repair it.

When i replaced my lines i used regular rubber lines and saved some of the original lines for patch work. I didnt buy any hard lines. One thing i did was saved the double line that comes right off the IWE actuator, because there are two connections of the actuator, the big one is the vacuum line the little one is the vent line. I then used a razor blade and split the double line so i could reuse the vent line cause its quite a bit smaller. But im sure you can buy some of that size hose as well.

To see if your IWEs are disengageing while your in 2WD is very simple. Make sure your in 2WD and then just jack the front of the truck up so the tires are not touching the ground. Turn the truck on, then go back to the front of the truck and spin each wheel and see if the half shafts turn with each wheel. If they do not turn then you are good to go, if they are turning then they are not releasing. Give the truck a couple seconds from the time you turn it on till you spin a tire, it takes just a few seconds for the vacuum to build and replease the actuators. Usually by the time you start the truck and walk back to the front its enough time.

Another way to check if the actuators are disengaging is do what i did. After i replaced all the line i cut the line that comes out of the solenoid about half way between the solenoid and where that line spits to go to each wheel. I then put a T in the line, and use it as like a diagnostic port if you will. i connected a long peice of vacuum hose to it and ran it out from under the hood up by the passenger side cowl and then in through the passenger side window, i then connected my vacuum guage to it. This then gives me the ability to watch the vaccum while i was driving. This helped after i replaced the actuators and still got the grind cause i was able to see that while under load i was loosing vacuum to the point where the IWEs tried to engage (which is what everyones does when it goes bad, load equals low vacuum, thats what the check valves are for to hold the high vacuum while under load to keep a continuous high vacuum scenerio) This testing capability will show you exactly where your vacuum is while driving. Then when im done testing i disconnect the extra hose and plug off the T in the line. This gives you a real good feeling of how the system works, you will see you vacuum build up when you turn the truck on, and if you have a leak, you will see it drop and as soon as the vacuum hits 5 bar, you will hear the grinding and see the guage start jumping.

Then after you turn the truck off, you willl hear a quick pssssssssss, a couple seconds after you turn the truck off. Thats the solenoid releasing the vacuum which locks the hubs in. At this point with the truck off and vacuum released if you spin a wheel you will see the half shafts turn.

Got it?


JWILLY....The CV boot does not (in my knowledge) hold any vacuum from anywhere. So no, the tear will not effect vacuum whatsoever. But what the tear will do is allow moisture and dirt to enter the boot where the grease and bearings are located. After some exposure, the contaminates could damage the bearings and break down the grease. If you are going to tear down the one side to replace the IWE then i would replace that boot as well, you will already have that all apart anyway. Or if you take it somewhere just have them do it as well. A couple dollars now for a boot is alot better than a lot of dollars later for all new CV bearings or new half shaft.

I told you, your grinding would go away after you disconnected the lines. Now you need to troubleshoot everything with a vacuum guage to determine if the leak is a bad IWE, hose, check valve, solenoid, or vacuum tank. A leak in anyone of those can cause the problem your experiencing. Good luck. And read through my very first post in this thread for testing.

 

xj
I appreciate all the work you have done on the IWE issues it has been very informative. I have an '08 F150 FX4 Screw that I believe is experiencing this issue. I waas on the interstate yesterday running about 75 mph when I heard a light grinding or hissing noise. It went away and then came back and went away. This occurred on my 125 mile trek to hunt. On my way home I experienced the noise again and I exited the interstate. Upon approaching the stop sign the noise continued and when I turned right I heard a clunk and then the noise went away. I switched to 4x4 Hi and then back to 2wd Hi and I made it home with out additional noise. Being an 08 I have the ssolenoid with the cover. I made a 800 plus mile trip last weekend and noticed my mpg was BAD! 14 to 15 on the highway. What suggestions do you have? Check valves, vaccum leak, actuators? Please let me know. Thanks again for your work and help!
Phill

 

PCAVENDER, my suggestion is if its an 08, take it to the dealership and explain your situation, im assuming your still under warranty. But we all know what assuming does......Anyway, there are too many components that can fail to give you this scenerio that i cannot give you any information except, if you really want to figure it out before you take it in (if under warranty) get a good vacuum guage and go through the testing procedures and pin point what has failed. My guess as to what happened is that whatever was causing the vacuum leak and giving you the grinding noise finally gave out, allowing the wheel ends to engage (the clunk) and now they wont disengage, giving you bad gas mileage because you truck is now having to push the front rotating parts. This is not a bad scenerio to be in if the fronts stay locked in because the front is now locked and not trying to lock and unlock all the time, grinding, and wearing the gear on the front axle ends. So as long as you dont hear the grinding the worse thing that is happening is your bad mileage until you get it to the dealer.

If your out of warranty and able to work on your vehicles with the appropriate tools, i would still get a good vacuum guage and pinpoint the problem using the methods on my first post in this thread. Then you will know what has happened and what is then needed to repair it.

 

xj
Thanks for the reply. Unfortunately I have 47,000 miles and I am out of warranty so I will take it to a freind's shop to be tested.
Phill

 

That's fine. Just take note of the components in the system and how to test them from previous posts. Its easy to miss the little things