O'kay, how about this........

[Erich Zeppelin]

1999 Expedition E.B. rear air bags won't air down. They seem to be at max inflation. How do I fix it? The front works like she should. up and down, no problem, but my ass is in the air like I have a 6" lift! Please keep in mind that I'm retarded and need step by step instructions!

 

[Thermo]

Erich, you can try following the air line forward and seeing where it goes. The next module you run into will be the valves. From there you can play and see what is going on. I wish I could be of more help, but my new computer does not like my old service CD's.

 

[Erich Zeppelin]

Well, since I have the only Expedition that has ever had this problem, I can only assume that Ford air suspensions are bulletproof and trouble free. I must have gotten a rare bad one. Can someone at least tell me how to let air OUT of the airbags? I cant even drive it.............

 

[tonydiv]

Since it's only half of the system that is screwing up I assume it it the level sensor.

The level sensor runs between the frame and the axle or a-arm. It is just a small linkage so it should be easy to find. It basically just tells the module what the distance is between the axle and the truck, so it can adjust the height. If that linkage is disconnected, damaged or stuck, then stuff like what is happening to you happens.


If you can carefully disconnect the linkage from the suspension and push the sensor arm 'up', the bags should deflate. Be careful when you're under the truck as it starts to lower.

 

[Erich Zeppelin]

Well, I shut down the air system, removed the ride height sensor, cleaned the connectors and the sensor moves freely. I will activate the system and try to see if I can move the sensor manually. Do I disconnect the lower mount and extend and retract the arm? And wow! nice ride Tony! someday I'll be able to afford that stuff........(I'm married, so I have no more money, no pride and I'm tired all the time....) lol! Do I need the truck running with the air suspension in the on position, then crawl under, remove the bottom clip of the sensor from the mount, then push the rod up and down slowly to see if it has an effect? If I do this and get nothing from the system, where do I check next? Thanks!

 

[tonydiv]

Well at that point we still can't rule out that the switch itself isn't bad. So there are two choices, either get the spec on the switch and put the multimeter on it, or find a parts place that has a liberal return policy on electrical parts and hook up a new switch to see if it triggers the air ride system. You could also ohm-out the front level sensor or even swap it to the rear to test it.

If the switch checks out, then it's time to move forward up the system and look at the control valve. I don't have that system on my truck, but if I remember correctly, usually when that valve dies, it doesn't inflate the bags at all. So that means it could just be an electrical connection to that control valve that could be the culprit.

Let me know how it goes. If things get sticky, maybe we can call on one of the guys here who has a good service manual.

 

[Erich Zeppelin]

Can you tell me where the control valve is, and a general description of what it look's like?

 

[Erich Zeppelin]

Still no luck getting the rear airbags to empty. I found a piece that looks like a large tire air valve located above the load sensor, can I bleed the system from that? It looks like a deep well socket will fit on it........... Is this the pressure relief valve? (PRV)

 

[uponthehorizon]

same issue over inflated air bags after heavy trailer load

I see your issue was 5 years ago, curious if you ever got it sorted out and what the solution was?
I have had the same issue occur after having a trailer load with a lot of tongue weight pressing down and the hitch.
System adjusts fine to the trailer, but does not return to level after the trailer is unhooked after the heavy load? The rear suspension does not deflate and beyond looking idiotic it's dangerous to drive because the back tires end up bunny hopping reducing tire contact with the road surface without the necessary travel in the suspension. Wrong array of whoops in the road surface can throw the rear of the vehicle askew enough to cause a roll over.