So I recently purchased a 2000 Navigator 4x4 with LLS. I bought it for a good price knowing that the alignment needed repair and that the tires needed to be replaced. Well I took it to my mechanic for the alignment and was told that it needed upper and lower balljoints and the stabilizer linkages replaced. Well since I could not really afford the $900 quoted. I replaced the lower balljoints, upper control arms, and the linkages. I used aftermarket control arms( the driver side did not have the notches for the height sensor) so I eyeballed it. Note that besides the tire wear and a slight pull to the right, I couldn't tell there was suspension or alignment issues. So after replacing these parts and before getting the alignment done, there was a stiffness to the steering and a slight click turning to the right. Well I get the alignment done and everything feels great. So today, I went to get new tires and when I left and was up the road several miles, the "chk sups" light comes on. I pulled over and thinking that they switched the LLS switch off, put it was on so I turned it off then back on. The light went out. I've driven around afterwards several times and everytime the light comes on but after shutting the ignition off and back on the light goes away. Could it be the height sensor? Could it be that the airbags caught a leak after being extended while having the tires done? BTW I still hear the compressor come on. Where should I start? Thanks in advance.

 

I would start with the height sensor by making sure the attachment point is in the same place as with the old control arm.

 

I have checked the sensor position and made a small adjustment. Although I also found that i was missing a bolt that holds on the caliper bracket, which I replaced. But still I am getting a rough ride and every so often I get the 'CHK SUSP' light. It goes away after cycling the ignition though. Also I dont hear the compressor running anymore. I am not sure where to start. I do know that I dont see any signs of leakage on the front air shocks and I dont see the a lot of sag at the rear end either. What to check now?

 

Does it air up to the correct height. This issue should be quite easy with the ford scan tools. Most likely suspect is the sensors and you need the ford scan tool to recalibrate if the height sensors are changed. The air ride suspension on these Navigators provide a very nice ride when they are working but are very expensive to repair and they do fail. If its just one height sensor in the front you are probably talking 350 at a Ford shop. At least that is what I last paid for one.