I have 2001 Lincon Navigator 2x4 and had both rear suspension down. I park my navi for 3days and notice that the rear part of the vehicle was low and as soon as I turn on the car compressor kicks which seems normal to me. While riding I feel all the bumpy ride and feels like I'm driving a lowerd vehicle. As soon as I reach my destination the rear part of my navi still down low. And while driving the compressor keeps coming on every 5mins. I went to my mechanic to check what the problem and he said that both rear solinoid was bad. I thought it was the rear air suspension but he said that both air suspension still holds small amount of air and probably have leak on the solinoid O ring. I do get the parts but after reading all the treads online it seams to have more problem can cause the dropping of the rear suspension. I don't want to buy all those expensive parts and finding out that's not the problem. Any one can help or had same problem??

 

mines also did it a while back like 2 days ago but it hasnt done it ever since and that was the first time its ever did it. You can try checkin the rear hight sensor it might have move down but then again you did mention the compressor coming on every 5min so there must be a leak, if you do decide to do something about it try coil over convertions

 

Where can I find the rear hight sensor??

 

The rear sensor is in the center of the rear frame over the axle. I suggest that you put the t-case into 4 low and while it's sitting still you air the suspension all the way up. Turn the suspension switch off and let it sit for a day or so. If it stays up you will have to check the solenoids in the lines going to the rear air springs, there may be a leak or a defective part in the system. The first place I would check would be the air coupler near the steering shaft and master brake cylinder, under the hood. The coupler is a fairly common fail point and they do crack and leak while they appear to be good. Soapy water is the best way to check all of your connections to find air leaks.