Lincoln Forum: Air suspension concerns
Results 1 to 5 of 5
Thread: Air suspension concerns
05-19-2017, 07:07 PM #1Junior Member
- Join Date
- May 2017
Air suspension concerns
Recently got this 05 town car and I noticed the car had loss of power on the top end so I decided to replace the fuel filter. I jacked the car up (withought knowing) I should have hit the switch in the trunk for the air ride off. The fuel line ended up having a leak where it connects to the filter. I just removed the clamp holding the filter in place and before I could even wiggle it out the bracket it started leaking... I decided not to fool with it and let the shop do this. Anyway!
I lowered the car and it sank real low in the back. I thought I ruined the air ride. But a quick search said turning the key on for a while should pump it back up. I go out and do this and the air pump kicks in (always does) and the rear raised itself and looked normal. I heard a slight squealing/whistle type sound coming from each side in the rear and thought ok I definitely have a leak but it eventually stopped. The rear end has never sank before..
Why did this happen after jacking it up? What all could be harmed since I didn't switch the air ride off? Since the air pump comes on frequently is it safe to say I have leaks? Its everytime I have used the car since getting it a few weeks ago.
Im really concerned I have found another problem on top of the fuel leak, plus I have other issues im working on such as plugs and cylinder 5 coil needing replaced. I wasn't expecting this but im still satisfied with the car thus far...
Thank you! Sorry for such a long post.
05-19-2017, 09:13 PM #2
If you do not turn the air suspension off in the trunk, the air suspension is active. So as you raised the car the level sensor at the rear axle showed the rear suspension is too high, and communicated that to the air suspension module. The module then opens the valve at the compressor to bleed air from the system, but the car keeps rising and the module keeps bleeding air until both air springs are "empty" of air. When you lower the car there is no air for the springs to support the car and it rests on the bump stops. Turning on the ign switch activates the module that sees the rear height sensor is low and powers the compressor until car reaches proper height according to height sensor. Don't do this too often.
A system in perfect shape will lower the suspension height when you leave the car after a period of time. When you get back in the car and turn on the ign the air suspension system brings the ride height back up to normal in about 10 seconds or so. While driving there is a long delay before the module will change the ride height, typically when weight is added or removed from the car.
Good luck with your new car.
05-20-2017, 11:29 AM #3
I concur with Town's post. It sounds like your air suspension is working properly.
05-22-2017, 08:06 PM #4Junior Member
- Join Date
- May 2017
Great explanation! But, is it normal for it to sink some after jacking up if the switch is off? Thanks guys..
05-23-2017, 07:37 AM #5
When the air suspension switch is off the entire system is off so no venting can occur. Are you determining the amount of "sink" by measuring from the ground to fender lip or just by eye?. There is a certain amount of friction in the whole suspension so when the car is let down from the jack the ride height will be higher than normal. It is always recommended to press the rear down if you are going to make adjustments such as replacing height sensor. Otherwise the car will settle to ride height over a short time.
You need to establish a base ride height for your car. So after driving for a while park on a flat surface and leave the engine running (to ensure against venting with the ign turned off) and measure from the ground to the underside of fender lip at the wheel center line (for 4 measurements). The side to side measurements will likely be about a half inch different which is the factory tolerance. All tires should be inflated to recommended pressures. Then you turn off the ignition and remove the key and leave the car for a few hours. On return measure the ride height as before but without touching the ignition, and the rear should have dropped about an inch or so. Now turn on the ign and exit the car and time the compressor on time to raise the car to the normal ride height and again measure the fender clearance which should be the same as the original measurements. Compressor run time will indicate the health of the components, 10 to 30 seconds would be very good.