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How a Suspension Air Compressor Works
Suspension Air Compressor
Vehicles equipped with self-leveling suspensions, or ride-height adjustable suspensions
are equipped with an on-board air compressor. There are even aftermarket overload
springs and air suspension bags that utilize an on-board compressor system. In this
article we will explain what the compressor does and some of the signs that yours
may be going out.Self-leveling suspensions have been around for many years, from luxury cars to
SUV’s the theory remains the same; when excessive load changes the ride height of
a vehicle, air bags coupled with height sensors and a compressor compensate for
the load and bring the vehicle back to level, restoring ride and control. Some vehicles,
such as Land Rovers have suspension height selectors
for different situations; entry into the vehicle (Lower), off-road situations (higher)
and highway use (Middle), all of these use an air compressor to achieve their goal.At the heart of these systems is the compressor. All air compressors work on
the same principle; take outside air (already at 14.7 psi), and by means of veins,
pistons or screws compress the air into a smaller area, thus creating higher pressure
or psi (pounds per square inch). Some systems use a storage tank that the compressor
fills to keep things working, others have pressure switches in the bags that tell
the compressor when to stop filling them, coupled with height sensor information.
Air compressors in vehicles tend to be fairly small, but powerful units, usually
with a maximum working pressure of around 150 psi. Their compact size and high working
pressures create a lot of heat, which can cause compressor failure if the unit runs
for too long of a time. This is common in a vehicle where there is a leak in the
suspension and the compressor has to run continuously or many times in a short period
of time to keep the vehicle level.
Some air compressors have their own internal check valves to keep the system
full; others rely on valves at the air bags, storage tanks or at the valve block
(Land Rover). These valves are also a common cause of compressor failure due to
excessive run time and or overheating. When replacing the air compressor in your
vehicle there are any choices. There is a large aftermarket parts source for these
vehicles as compressor failure is fairly common. Always use an OEM (Original Equipment
Manufacturer) part or the equivalent. A cheaper compressor won’t last as long and
may cause suspension failure, which can cause loss of control of the vehicle.Replacing the compressor in your vehicle isn’t a real complex procedure, but
as always proper safety attire should be worn, and it is best to refer to a
shop manual for
your vehicle to see if there are any special relearn procedures or precautions that
should be taken to avoid injury and to assure the repair is done correctly. Usually
you can do the repair with the basic tools; socket set, screwdrivers, wrenches.
When replacing the compressor, you should also replace any sealing o’rings that
you have disturbed; this may avoid a leak in the future that could damage your new
compressor.
If further technical assistance is needed,
ask our team of certified car repair technicians.
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