I have a 98 Eddie Bauer Expedition with 130k miles. Recently I have noticed the suspension compressor coming on a lot more than I have previously noticed. I have parked the car on level ground and measured a drop of a quarter inch over night at the rear bumper - is this normal? How often should the compressor come on? I have checked everywhere for leaks and cannot find any.

 

maybe a hole in the bag? spray some soapy water on it and look around. try all the connections.

 

Thanks, I spet all last night spraying soapy water on anything suspension related and no bubles! I was wondering if it could be the solenoid on the air bag?

 

Try spraying soapy water on air bags and air lines when compressor is runnnig and suspension is supported by inflated air bags and not the rubber bumpers on the frame. Currently have similar symptoms on my 97 F250 lite duty equipped with air suspension. Air bags keep deflating - compressor and sensors are new and working OK. sprayed sopay water at bottom of of air bags while compressor was running and air bags were inflated enough to be supporting frame. Witnessed the dreaded bubbles until bags defalted to point that frame was supported on rubber bumpers.

 

How often is often? (how often does it run)

Is this 2wd or 4wd?

You say you are getting a 1/4" drop overnight. Really, that's not much nor is it really anything to be concerned about. But if you are and want to check, then look into a few things.

1) Check the union under the hood, that feeds the rear bags. If you have an original union, it might need to be replaced by a new style union. Soapy water will work. look for hairline cracks near the edges.

2) You may notice the compressor more b/c its louder than normal? If so, this might just be a mounting issue, you may need to upgrade to the new mounting bracket.

3) Determine how often the compressor runs. Does it do it every 15 min, every 30min, once every few hours, only after you start the truck (after it has sat for a bit), etc. Determining how often it is running can help determine if you really have a leak or not.


Edit; A drop when its turned off can happen at times. For instance, mine will lower about an 1" after i turn it off and it has a light to no load (gas included). If it has a full tank and peeps in the car, it will not lower once turned off.

Its hard to say how often the compressor should run, b/c this again is determined by the load. Unloaded, mine will only run once its started and maybe once every few hours after that. loaded, it might run when its started and possible once an hour. Its hard to say what is right. But, if its running a few times per hour unloaded, then its possible you have a leak.

 

Thanks for the info. The truck is a 4wd expedition. I have checked the union and no leak though I am going to replace it. The comp. always runs when I start the car, after that it varies. I am beginning to think its the mounts on the compressor and the airbags as I noticed some very small cracks but no ,eaks in the bags. Another post said that it may only leak once the bags are fully inflated - this sounds feasable so i will change then shortly. Thanks bjh

 

I have a 98 wlt with air suspention as well, 2wd, once everyone is out of the truck and all doors are closed I will hear my selenoid do 3 clicks and my trucks will drop juist about 1". if left over night the bumper will be knee hight, I have been told that it is normal.

 

The air bags on the expy will show a leak any time there is air in the bag and the truck is not on the bump stops. Since yours only drops a 1/4" (still basically full), you should have seen any leaks the first time you did it.

Have you checked the front shocks and their respective lines? What about the "T" fitting that splits the rear air line to the two bags?

I still think everything sounds fine though.

 

I am quite a newby here, I just purchased a 2000 expy the compressor came on alot, and loud. I read alot on the boards about it. I found out that I needed to order a kit that had sound dampening washers-and a newly designed bracket.

In reading all those posts, people said after they fixed it they couldnt hear the air compressor at ALL. they talked of how they were questioning if it was really on.

so MY question to you is, Is it possible that over time your bracket has worn down to where you hear it now, where you didnt even notice when it came on before?
The expy is designed to raise up when you start it and go down when its not in use.

 

Only the 4WD are suppose to drop once the engine is shut off. 2wd are to stay leveled

 

Thanks, for the reply, That could well be it, I plan to change it.

 

I used to think the same thing, but mine will lower a bit when I get out. maybe, I am just too much of a fat *** and causing it to over inflate, so it has to lower to "normal" height when i get out.......

 

This is incorrect. Our 2WD always drops overnight or after about 3 hrs.
This is standard.

 

I stand corrected then, thanx for the heads up guys!