1999 Air Suspension

[princess936352003]

My 1999 Lincoln Navigator All wheel drive seems to be having a problem with the air suspension. The back of the truck looks like a low rider car, and has a horrible ride, it is super bumpy. I don't much about cars so i was hoping to get some info and advice on the problem. I am really hoping it is not going to be some really expensive thing to fix. :(

[Nick]

Your rear air suspension sounds like it is leaking. You will need to verify this by allowing the truck to reach normal ride height and then manually shutting off the suspension. If any corner or end sinks, you have a leak. Try and measure the height at each corner. See if you can tell which corner drops first. This one will have the biggest leak or the only leak. A leak in one corner will drop that end because one spring cannot support 50% of the vehicle weight. You can also use a solution of soapy water or Windex to see where the leak is. You need to spray the entire air spring and the air spring solenoid at the top of the spring. It will have a nylon air line going into it. The repairs should be made fairly quickly as you do not want moisture to enter the system nor do you want to burn out the compressor trying to compensate for a leak.

Repair costs will be fairly minimal if you can do the work yourself. If you need to take it to the dealer, it will get more expensive. www.americanairsuspension.com (http://www.americanairsuspension.com) sells parts for your truck. The OE Ford parts usually last the longest and they can get you the parts you need at a disounted price. You may also be able to buy aftermarket parts, which will be cheaper, but their durability is unknown.

[princess936352003]

Thanks for responding to the message I posted. Can I bother you a little bit more by asking you how or what I need to do to allow the truck to reach its normal height and how will I know it has reached it. Also how do I manually turn off the suspension? I have never dealt with any car problems so I'm really ignorant in this subject, but I do want to try to keep my repair cost as minimal as possible.

[Nick]

If the truck's air suspension compressor is still good and if the system functions normally besides the leak(s), the truck should raise to normal height on its own after vehicle start or if the key is placed in run. The door(s) must be closed to signal the computer to begin checking ride height and fill or vent if necessary, however. If the air suspension compressor times out, meaning that it could not fill the springs within the alloted time as dictated by the computer, then a warning light or a warning message to the effect of "Check Air Suspension" will notify you that something has not worked properly. This is verified by visual inspection of the vehicle to see if it is level. If the truck failed to raise itself, you will need to try this next step.

I'm not sure if your truck has it, as I have never had the opportunity to peak under the hood of a Navigator, but if you locate the air suspension compressor, it will have 2-4 colored, plastic lines going into a black plastic canister which is attached to a metal pump. Ford has places this pump in a few different locations depending on the model. Places to check are along the driver and passenger inner fenders next to the engine or in the front of the car by the radiator/grille/front lamp area. There is also a possibility that the compressor is hidden away in the front. Hopefully, someone else can chime in with the proper location and more details. The nylon air lines for the suspension may be shrouded for a tidier appearance. See if you can find a valve that looks like a tire valve. This is type of valve is a Schraeder valve. If you have or can borrow a shop air compressor, you can try to aid the suspension during the fill sequence. The fill sequence occurs immediately following engine start up or when the ignition is placed in run. Air will only enter or leave the springs when the air suspension solenoids are open (assuming no leaks). These solenoids are valves that check air movement into and out of the springs. You should be able to hear them make a "click" when they open or close. You should hear the air suspension compressor turn on and hum during this fill sequence. Immediately after the air spring solenoids open, you will want to connect a hose to the suspension compressor as you would a tire. The compressor must be rated with an output of 125 psi or greater to be of any use. Anything less will have no effect on the car. Your local gas station air pumps, for instance, cannot be used to manually fill the suspension. If this works, your truck should begin to raise off the ground and it should achieve normal height after a certain time. It will take about 30 seconds or less. The computer times it all and it will close the solenoids once the time limit is reached. After this event, you will have to restart the fill sequence if you need to add any more air. After it has reached normal height, it should look like it used to before the problem.

After the vehicle is at normal height, you should shut off the air suspension. To do this, locate the air suspension switch. It's location will be disclosed in the owners manual. The switch should be in the back behind the 3rd row seat on the left or right side. It will be covered by a trim panel or access door. It's location is probably even marked.

While the truck is at normal height, you can probably crawl underneath and begin looking for leaks in the air springs. They are large rubber bladders with plastic bases. Sure signs of deteriorating springs are cracks in the rubber. They are usually down towards the bottom as the rubber folds over the plastic base. The best view of the air suspension is obtained through removal of the wheel. You will need a large floor jack, a 3 ton is preferable, and matching jack stands to safely raise and secure the vehicle in the air. Under no circumstance should you be under the truck when it is supported by the jack alone, a combination of the jack and a stand, or when the spare tire jack is used. The spare tire jack is only an emergency lifting device. You can use the wheels you have taken off as a safeguard by placing them under the vehicle. Should the truck fall, the wheel(s) will be there to maintain a minimum clearance. You should be fine, however, with two high rated jack stands and an object like a brick to use as a wheel chock in the front. With the wheel off, you can see how easy it will be to replace the air spring. It should require only simple hand tools. Any high school student with a little mechanical inclinaton should be able to change it. It really should be that simple.

If you have any more questions, feel free to ask. That's the purpose of this board. smile.gif Good luck and have fun!

[Air Suspension]

There are to lines to the dryer, and the comp. is front of the windshield washer fill reservoir. It is probably you comp... Or relay. From my experience. The relay is behind the front bumper under the comp. You lie down and look up between the bumper and chasse.