F 'd my truck up again - 4x4 issues
 

Hello
I've been having issues with 4x4 for awhile. But things just got much worse.
Previously I had an issue when in some sand with trailer, switched to 4L but only went to 4H initially . Started moving and slammed hard with a clank bang, and just bad noise and no 4.
In 2x occasionally I'd hear a light wind blowing cards in wheel spokes type sound. Not a huge deal.
Do I decided to start working on it.
Yesterday . I'm out in remote desert at work. And hardcore rain came as I was readying to head out the 15 mile dirt wash road . Thought I'd swap my new iwe solenoid before. (Maybe it'll help (maybe I'll need 4x)
In a hurry as I've got ****s to dos. Swapped solenoid and recalled hearing of blowing out the vac lines as known to get water . Do I disconnected the lines at solenoid and at hubs. And blew some compressed air into what I thought was a line with open ends. F ! A loud pop ! Blew something out! Oh man. Went on my phone googed it. Thought I blew out my vac hub actuator deal. Which I happened to have got new, in my attempt to fix this.
So I swapped in the new vac hubs in a hurry. On the way out the road started getting the old sound but much worse. No sound in 4. Both L and H seem to work. But I've got a feeling something is quite wrong. I'm in the middle of nowhere really. What can I do to try and adress this? I've got some vac line. But no pump tester.
What could I gave damaged when I blew air in the larger line?
Any advice?
How much damage can occur. I drive back very slow in 4 H.
Man. Any help thoughts ideas?
Other than stating the obvious of my ignorant F ups .

So 4L and 4H both work now after replacing IWE solenoid and Iwe hun actuators? But your hearing aome sort of sound?


On my 06 f150 i can never be driving and switch it to 4H i get all kinds of noises... i ALWAYS have to stop and switch to 4x4 never fails and works like a dream

My guess would be the vacuum reservoir, its located between the battery and the fender. It's purpose is to help supply vacuum in situations where engine vacuum is low, such as WOT. I almost did the same thing when I was checking for a leak in the reservoir, luckily I had it in my hand so removed the compressed air when I saw it expand.

If it's cracked you will have a vacuum leak and will hear air sucking near the battery.

You just replaced your IWE actuators right? So you know they aren't seized, so you could just remove vacuum and leave your hubs fully engaged. Easiest way to do that is disconnect the vacuum line from the IWE solenoid and plug both ports of the vacuum connector (a pop rivet works great). The actuators are in the locked position until vacuum is applied, removing vacuum will leave the hubs engaged all the time but won't hurt anything and you can engage and disengage 4x4 with the transfer case as normal.

As usual, you should not drive with 4x4 engaged on dry non slipery surfaces or you could cause damage. You mentioned driving in 4H, was this due to the conditions or because you were concerned about something mechanical? If it's because the sucking sound goes away in 4x4, that will go away in 2H as well after you disconnect and plug the lines like I described.

You could have popped one of the three one way valves on your vacuum lines. I'd pull them one at a time and see if you can blow through one end and try to suck the air through the same end to see if the one way valve is functioning correctly.

Our trucks have SOTF 4WD system... don't know why you have to stop to switch to 4WD HI...you can select this mode up to 55mph...

Yah, i know it has swift on fly, im not sure why its doing what is doing.. wheh i first bought truck i had to replace both actuators IWE solenoid.. 4x4 works fine just cant be driving and switch into 4x4 otherwise it grinds till i slow down and then it locks in

Thanks for the replays guys .
I drove in 4h down many mikes of dirt. When in town went 2x and the grind sound began to increase in badness . Do I went 4h and slow as possible. Trying to not go over 35-40 mpg. In a 55;

Ended up pulling the lines off at solenoid (in my mind to hopefully ensure the 4 x was fully engaged. Didn't plug lines. I noticed a valve I believe, wondering what it was at a connection. Looked like something I've seen on air line of a hvlp sprayer . I will try to locate all 3 and blow and suck.
How do I check the reservoir ? Sounded like a big balloon popped. Was that the res?
Thanks for the help . Feel I've got a solid starting point to hopefully work this out.
Gratitude
Wright -

I checked the one way check valves. The two that I could find. Removed battery in search of the air pressure reservoir . There's a rectangular box behind batt towards passenger wheel with one hose feeding into it. Opened the box a little. Is this small box the res?
What is the large cylinder on drivers side against firewall? Seems a main hub for vac lines? Or something important. Could I have damaged this when I pressurized the system with 50lbs of air. ? The balloon popping sound. How much could have been affected by this error?
The two check valves I found worked fine. Air flows through one way and not other.
Thanks for your help men . Trying to get this diagnosed today as a friendly neighbor offered to pick up any parts I may need tomorrow. So if I figure it out can order part(s) and have ready tomorrow saving me a long journey on a sketch motorbike or possibly furthering damage to truck .
Trying to see the positives. However stressful being on a remote jobsite with no solid transport. I'm beginning to further educate or familiarize with this truck and it's systems.
Ever thankful to be able to reach out for help!

Check this post to see where the reservoir and check valves are. Go back and read the first few posts by @VTX1800N1, very useful information.

It's worth testing the check valves for sure, but I think you will find the reservoir is toast. You would test it by using a vacuum pump, it should hold vacuum.

When you remove the check valves make note of the orientation so you put it back on the same way. Oh...and blow either side, don't suck or you will end up with a mouth full of nastiness...don't ask how I know. You should only be able to blow at one side.

The grinding you were hearing was probably the teeth of the IWE actuator and hubs as they were trying to disengage. Since you have a leak in your vacuum there isn't enough vacuum to pull the collar off the hubs so it is only partially disengaging.

Yes, the small box behind the battery is the vacuum reservoir. If you can open it...it's toast for sure.

Are you talking about the brake booster? You said in your first post that you removed the vacuum lines from the IWE solenoid and the actuators before blowing air in the lines so you wouldn't have done any damage there, besides, I think you'd notice as you'd have some issues trying to stop your rig :)

If you did remove the lines as described, you could only have damaged the lines up to the IWE solenoid, one of the check valves and/or the vacuum resevoir.

Have you tried to drive the truck in 2H with the vacuum lines disconnected at the IWE solenoid? From everything you have described, you should have no trouble driving with this setup. Both two and four wheel drive should work just fine with the vacuum lines disconnected. The grinding noise you were describing should only occur in 2H with the vacuum lines connected.

Make sure you plug the vacuum lines though, you only need to plug the supply line from the brake booster, but both would be better to keep debris from getting in the lines down to your new IWE actuators. If memory serves me correctly, it's the top line of the IWE solenoid.