Just called the dealership they have the solenoid in stock at $28, so im going to pick one up after work and give it a try, if that doesnt fix my vacuum problem then i will know its the lines. My solenoid on the truck is one of the ones that doesnt have the rain sheild on it, so i guess it could be shorted out, but i know it doenst have water in the line, i checked that last night and found none.

 

I don't see a problem making your own...but make sure that's your problem before you start buying parts! Try disconnecting the vacuum lines at the solenoid, plug that end, and apply a vacuum to the other side of both lines and see if it holds vacuum. This'll tell you if you have a problem with your lines.

Can you hook a vacuum gauge to the solenoid and test for vacuum at the source? Try that before buying another one, and verify that's your problem.

Over the last few years, I've blown way to much money on unnecessary parts...gets pricey after awhile....

 

Im going to check some of the vacuum specs again tonight, im going to stop on my way home from work and get the soleniod, if i dont need it ill take it back, its on my way home, and will save me a trip later. Im going to be doing some plugging of lines and checking of vacuum and see if i can narrow it down, but it just is weird that the drivers side hose has vacuum and the passenger side doesnt. I would think if there was a break somewhere that the entire hose system would leak and not work cause they are both connected. unless there are some check valves or something.

My plan if the hose is leaky is to pull the old lines out and buy just some vacuum hose and a T and a couple butt connectors and make my own line from the solenoid to the wheel ends and run the line where i can access them easily cause the stock ones are sort of run in some tight spaces.

 

I was just reading all this for the heck of it, and man am I glad I don't have this problem. Sounds like quite the head ache. Good Luck

 

Ok, here is the update, not how i wanted it to go, but when does it ever? i went ahead and changed out the solenoid just because it is the updated one with the rain cover. I checked vacuum at different places, solenoid, hoses at wheels, and the fitting at the actuator. I had good vacuum at the solenoid. I found a crack in one spot in the lines, but that was the least of the problem. I checked the actuators, passenger side i can build up and hold vacuum. Driver side actuator i cant, so guess what, im going to be changing the actuator at the drivers side. Not what i want to do. But here is what i found. Because of the actuator not taking any vacuum it wont let the whole system take vacuum so both side stay continuously locked in which from what i read is better than one side or both sides trying to lock in and grind and what not. So i made a new line going from the soleniod to both wheels, i put a T in the line and took one line to each wheel. I took the old double line at the wheel and used a razor blade and split the big line from the little line so i could reuse the little breather line. I cut out the old vacuum line where i could since im not using it. After i ran the new lines i plugged the line at the wheel at the driver side cause the actuator is not taking vacuum and then hooked my guage up to the passenger side wheel and turned the truck on. It built vacuum and held it so my system is tight and working. I then put the line back on the wheel on the passenger side and hooked my guage up to the driver side hose and turned the truck on, it built pressure and held. So my hoses are good and the passenger side actuator is holding vacuum. Before i did all of this i jacked up the truck and spun the wheels just to verifly what was moving with the truck on. Half axles are moving as well as the front drive shaft. When i applied vacuum to the passenger side actuator and spun the wheel only the wheel spun, so that made me feel a little better. So the dealership has the actuators and i should have grabbed one while i was there just in case, but i didnt so ill pick one up tommorow on my way home from work and put it in tommorow night. Im just really convinced now that all that extra rotating mass is giving me my vibration and possible the wandering of the truck. Its just not the way i wanted to spend my friday night. So now the question is what is the best way to get the actuators out? I have a good idea, but what all do i need to do and what is easiest? Do i need to take the spindle nut off and then do i need to get a new one? Thanks guys!

 

Ok, i took work off today to fix my truck cause it was bothering me. And i replaced the driver side actuator already. Not to hard to do after i read a couple posts here and ther on how to do it. And the driver side was deffinately shot, the seal/boot around the actuator was all ripped. I put the new one on and checked the vacuum, it holds, so the vacuum leak is fixed. I will post pictures later cause my computer is going on the fritz. I picked up two of the actuators cause i figure i might as well do both cause i know as soon as i fix one the other will go. So im off the to do the other side. Thanks!

 

I just finsihed the passneger side and it went smoother than the driver, probably cause i knew what i was doing after the first one. After i was done i started the truck and spun the wheels, and only the wheels turned! YAY! The one i took out of the passenger side was still working so i plan to hang onto it just in case. Im going to take it for a ride here in a minute and see what i feel.

The actuators at my dealership were $103 a peice, ive noticed that my dealership seems to be a little higher priced than most, but i wanted to get it done and they had them. i think Y2KFordParts has them for alot cheaper if you want to order them online. If i wasnt in a hurry to do it i would have ordered them there, but it takes about a week for me to get stuff from them cause of the distance between.

For those you wanting to do this, and have tore parts off the front end of you truck before, its cake.

 

Ok, not so good. I went for a ride and when i get in high RPMs and the vacuum drops (from what i read about the RPMs and vacumm) i can here one or both actuators trying to engage. So i let off and it goes away so i kept out of the gas on the way home, only drove a couple miles. So i checked allthe vacuum at idle. I get 19.5 from the intake, and at the hose ends at the wheel. Everything pumps up and holds vacuum, all the lines and hubs. I cant tell if both hubs are trying to engage or one of them. i might be tearing this thing back down and check that i put everything back together ok the first time. Any thoughts.

I also was blowing out some of the lines that i left on the truck and while blowing out the one line i heard a loud pop. So i pulled the battery out and the battery tray and found a little black box that is connected to the vacuum line coming off the intake, it Ts off right below the solenoid. So i pulled that out and what happened is the seem blew apart. So i bypassed that box and the line coming off the intake goes straight to the solenoid on goes to the solenoid and one to the black box, im guessing its a vacuum resivour(sp). This all happened after i drove the truck the first time and came back, so i know that didnt cause anything. Is it ok to bypass that vacuum resavour(sp) box. i get instant vacuum for the wheels now instead of it building up. Thanks.

 

ok, im ruling out that i put something together wrong, i just took it for a ride and with a long hose running into the cab to my vacuum guage and the pressure is dropping too far during load and high RPMs like going up a hill. All my hoses hold vacuum and i tried both solenoids that i have. Where is the vacuum? What else should i be looking at that could be causing low vacuum at the engine? Thanks!

 

Ok i expoxied the vacuum box back together and it holds 20 psi. I put it all back together and took it for a ride. It was much better. I only had the whine noise of the actuators once. As i watched the vacuum guage in the cab that i ran a long peice of hose from a T i put in the solenoid to wheel line, i could see as the engine went higher in RPMs and under load the vacuum would go down. At the point where i got the whine, i went from a dead stop and up a constant incline. Thats the only time i got it, but the vacuum fluctuated alot during the entire drive so here is my question now.

There is a check valve in the line coming off the intake, that line T's off and one end goes to the vacuum box and the other to the solenoid. If that check valve isnt closing completely will i see the constant change in vacuum from the engine. If so then if it was working correctly wouldnt it let the vacuum box build up with vacuum as with the lines to the wheel and hold that vacuum unless the the engine vacuum increased or there was a break in the system from the check valve to the wheels? Because here is what i found.

I pulled the check valve and sucked on the ends (keep it clean guys). The vacuum side i could freely pull air through. The other side i could still suck air but it was restrictive. I had another check valve in my tool box but the wrong size. When i sucked on that one i could freely pull air through one and not the other at all. This leads me to beleive that the check valve is only partially working and im seeing the fluctuation of the vacuum from the engine in my guage and every now and then its dipping down to the 5 lb mark and that is where i get the whine.

So now after i have fixed everything else in the vacuum system a little check valve which i beleive to be worn out is standing in my way. Do i sound like that is what is going on? I hope someone is reading this stuff cause no one is responding its just me rambling, but this may help someone else down the road.

 

Maybe you just need to give it another try and suck a little harder next time?

Sorry I could not resist






I am reading but have no idea on how to help.

 

im reading it... but i've never had my hubs apart so im not sure but from your last statement it looks like you have a bad check valve

 

I new someone was going to go there. Im going to head to the local NAPA in the morning to get a check valve, and im going to take my long hose (again, clean thoughts) with my guage on it and change the check valve in the parking lot and try it on the way home.

 

I replaced the check valve, took it for a ride and it went good for the first couple miles then the vacuum dropped again and started fluctuating again, so i went home and checked the check valve, it was ok, but then i found another check valve in the same supply line but up by the solenoid, i pulled it and it was completely shot, free flowing air both ways, so i went back to the parts store and got another one, put it in and took it for a ride, it went very well vacuum stayed up and it did fluctuate a little but only a few lbs here and there, im attributing that to the equalizing of pressure in the lines and that is allowing it to drop. But when i would get on it the pressure wouldnt drop too much, maybe a half a lb. I did notice while criuising on the highway that i had a constant slow leak down in pressure, never went below 14 lbs during the couple mile stretch i was on so it didnt hurt anything. So i went home again and checked the vacuum box and it isnt completely sealed i guess, i still get a slow leak down so i put more epoxy on it and im going to try it again. Good thing i have one on order. I think that is my problem now and im pretty confident that when i get the new one all my vacuum problems will be fixed. This vacuum stuff is enough to make me want to pull my hair out!

 

XJ, thank you for all of your posts on this problem. I'm assuming that the pull you referred to originally is gone after all of this work. If you didn't make a strong case for Ford offering the old fashioned mechanical 4X4 system, nothing will. If a company like Dynatrac is listening, develop a conversion kit like you make for the Super Duties and we'll buy it.

Greg B