OK, so I have an 04 5.4 4wd supercrew.. All of a sudden at certain speeds, or goin up inclines, I hear the grinding of what I know know to be my actuator on my driver side. Its not all the time, just when the truck is under a load. It stops as soon as I let off the accelerator. I tried going to 4HI at a lower speed when this was happening, and it stopped the issue. This let me know that I had an issue with the 4wd.. I started off by trying to keep it easy, checked the check valves first. One was allowing air both ways!! Score! problem solved right? Ran to the store and picked one up, and replaced it.. went for a drive.. same issue.. dang.. Ok, so seeing how I dont have access to a pump tester, I know it sounds ghetto, but tried testing some by blowing, and sucking (no dirty minds please).. Everything appeared to be ok, the best I can tell by that. SO I dove in headfirst to the actuator.. I got it off (finally.. freaking upper arm wouldnt let go), and pulled it out... I blew into the valve and it appeared to working properly... I started the engine, and hooked and unhooked the hose to it, and watched it work like it was supposed too... After all of that, I went back to hoses, and was checking the basic ones around the cllanoid sp? (which is the original one, I havent replaced it, because it appears to still be working fine).. I even checked the air reserve box to make sure it was holding a vaccum.. Very frustrated, right before coming back inside, I recheck the check valves one more time. The one I replaced is free flowing both ways again! WTC??? I used no canned air, nothing other than me blowing or sucking (again, no need for comments).. Could it have been me? Or possibly did it happen right after I replaced it, and if so, what could be causing it? SO those questions along with, does anyone know a for sure way to tell if an actuator is bad? I hate to order one when I dont even need it, and this one seems to be holding a vaccum.. Im completely lost, could really use some fresh perspective. Thanks a ton guys....
Then you really need to get a vacuum gauge. Everything might seem to work ok when blowing or sucking on the lines, but there could be a small leak. I say that because you said it only really happens when the truck is under load. That is when the engine is putting out the least vacuum. The system is designed to hold a high vacuum even when the engine drops in vacuum. So if you have a small leak somewhere and you get halfway up the hill, your "trapped" vacuum has leaked and dropped low enough to try and engage the actuators. The only real way to test all of this is to get a vacuum guage and start testing components and chunks of line. Sorry.
On getting the new actuator, you could buy one if your local ford dealership has them in stock and if you dont need it take it back. Even though the old one seemed fine, the vacuum gauge will show you when you pump it up if the vacuum is leaking out. And you will know for sure if its bad or not. On the check valve, i dont know what would cause the new one to give out, maybe just a flaw in the manufacturing, or maybe since you said it looked frail, ot wasnt one that was made for over a certain amount of vacuum. Or it could have just been sitting on the shelf for a while and dry rotted.
Thanks so much for the help. I am hoping to track down a vacuum pump today. Whenever I am testing, is there a certain amount of pumps I need to do? I sure dont want to put too much vacuum on the valves, or anything. Also, do you think that I should change out the solenoid? It appears to be working fine(goes into 4wd fine, light comes on, etc)? I really hate to spend alot of money on stuff that doesnt need replacing. But if you think that could be the culprit on causing the check valve to mess up (dont really see how) or the act to grind, I can replace it. Thinking through the system, if it were to leak some, (the sol that is) could it cause it? or shouldnt the check valve right on the other side of it stop the leak even if it did? That make sense?
When you pump it up, i would pump it up until the guage shows about 20 -25 bar. I think i read somewhere that the actuators engage and disengage at about 5-10. I always pumped mine up around 20, it doesnt take much.
You could swap out the solenoid, its only like $30-40 and would be an easy fix if that is the problem. Even though the 4ws seems to be going in and out fine, the solenoid can still be the cause of leak, the seals in it can be shot and allowing the vacuum to leak down.
Any help would be greatly appreciated. I am getting a grinding sound from the left front wheel while driving straight.. The sound stays the same when brakes are applied and does not change when selecting 4wd or 2wd.. I pulled the wheel off and had a look, but saw nothing unusual.. Any thoughts on steps to diagnose/repair the issue?
04 F-150 5.4 4x4
After reading the thread everything you need to know about IWE's here is what I have found out; after disconnecting the line from the intake at the check valve sound is still present whether in 4low,high or 2wd it gets a little quieter when turning right. I found that the vac line coming from the left IWE is broken.. I will get on replacing that as soon as I can.. my concern now is since disconnecting the vacuum from the intake to the check valve made no difference I was hoping to make it drivable until I could replace the vac line.. anyway since it made no difference does this likely mean there are more issues other than the broken vac line... I am moving next week so I desperately need to make this truck drivable.. Help!!
I actually had that happen when i did mine, i replaced both actuators then a couple months later it came back, come to find one of the actuators i put on went bad, i pulled it off and the ford garage flipped me a new one.
40s Rock, i dont know the history on what all was done on your truck, but if you just replaced actuators, it could be check valves failing, or a leak in a line somewhere, or the solenoid. Specially with 193K miles, it could be anything.
I would get a good vacuum guage and start checking everything. If you did the work before, than you know how it works, it shouldnt take that long checking some components and lines to find you problem.
I have a 2005 F-150 FX4 with 90,000 miles. This past winter I had been hearing this weird grinding noise at low rpms when my truck was under a slight load. I figured I was losing vacuum and that was what was causing it. The mechanic changed my vacuum line because there was a hole in it. Problem solved.
About a month ago my 4-wheel would not engage and disengage. I changed the IWE solenoid and everything worked fine.
Today, I decided to throw my truck in 4-wheel. It worked but then after I turned it off I noticed that this grinding noise would happen for a few seconds and then go away. I know there is still something funky with the system.
One of the mechanics told me a while back that I have a slight leak from my IWE (the boots?). When I took it to the ford dealership he said that I needed to replace the shift motor and solenoid (I only replaced the IWE solenoid). So I'm kind of stumped and don't want to spend any more money on something that will not solve the issue for good.
I would get a good vaccum guage and test the vacuum of the actuators behind the wheel, pump it up and check it to make sure they are both holding a vacuum and not leaking down. If one or both are leaking down at a considerable rate then you do have a actuator that is not allowing proper vaccum to build quickly when you turn it off, the grinding you hear is the acutuator partially unlocking from the axle, it stops when the vacuum has built up enough to over come the leak and completely dis-engage. If that is your problem, replace the problem acutuator. But if you have replaced lines and solenoid, the only thing left is to check the check valves and check the actuators.
Thanks for the write up on the IWE system, it's the best write up I've seen in years. Your detailed instructions walked me thru the entire system and after running a thorough vacuum check it turns out all I had to replace was a check valve. Thanks once again, I think I'll put you on my christmas list.