Low air suspension refers to the fifth wheel height from the ground. The suspension system (low air leaf) is a suspension system with a lower ride height and is used by many transportation companies because it allows their truck to hook up to a variety of trailers. In modern days, low air leaf has been replaced with Flex Air suspension (low air leaf is still available). Flex air has the same ride height but weighs several hundred pounds less, thus allowing the truck to haul more weight in the trailer.
Check to see if your tires are out of round.
my town car is sitting low because the air suspension is high at times.
air suspension may need checking
Does yours have air suspension on it. You may have a leak causing it to sit lower when you are not running. Ford Expeditions with air suspension is designed to lower when parked for easier access.
From the bottom of the frame, to the center of the axle housing, it is suppose to be 8¾" without a trailer. With the trailer, the measurement should be 8½"
Check the air bag suspension. Also, the pump may be bad.
It usually means that the air compressor cannot keep up with a preset demand for air. As long as the suspension is at normal height it is not dangerous. Iif you get the "too low" warning, you should not drive the car till it's repaired.
It senses the level of your car's rear. If it senses that the rear is too low due to weight, it sends a signal to actuate the leveling mechanism(ususally air suspension system)
It sounds like the vechile is in low range, shift back to high range. or possibly a fault with the air suspension system. maybe you have locked the air suspension in crawl mode
You have a problem with the air ride suspension. Sounds like a bad compressor or a leak.
Town cars have an air suspension system. There are air bags on the rear axle instead of springs. There are a lot of things that can go wrong: Leaks in the bags or lines. Pump not working. Fuses blown. Google "check air suspension". You can also buy a conversion kit that replaces it all with springs designed just for that. I paid $115 on eBay and am glad to be done with the air suspension.
The low air pressure warning switch on a 1998 Peterbilt truck is typically located on the air manifold near the firewall on the driver's side of the vehicle. It is usually attached to the air system components and can be identified by its electrical wiring connector. You may need to consult the vehicle's service manual for specific instructions on locating and servicing the switch.