americanairsuspension.com

Stay with the Air Suspension or Do an Air Suspension Conversion?
First things first.....all air compressors produce moisture, no matter the size. Bigger air compressors like whats in an auto repair shop or in most shade-tree mechanics garages, fuel air tools, blow sawdust and air up tires. Although the bigger ones produce more moisture than the smaller ones, the bigger ones have a tank with a way to easily drain the moisture from the system. Most people don't realize that an automotive air suspension system is just like an air compressor in their garage with one big difference between them. Because of all the low lying air lines and other parts(air springs - air struts) in the vehicle, there is no way to easily drain moisture out of the system.
You've heard automobile air suspension systems have a dryer that absorbs the moisture? That is true, but keep in mind 2 things.
#1) Having a dryer right off the air source is at best only 95% effective. The reason being, when working with pneumatics, you to have the dryer or collector a good 6 feet from the source. This is to allow the hot moisture filled air, time to cool a bit where the dryer can grab it. Not allowing it to cool down a tad makes the whole drying system ineffective, because the moist hot air will blow right past the dryer. When the vehicle is new, you'll never have this problem, because the new dryer has collected most of the moisture and not enough has collected in the system to cause problems.
#2) The dealer won't tell you this, but because they want you to keep buying air suspension parts and to come line their pockets later on when your out of warranty, but most dryers used on these automobile systems only have a lifespan of 4-5 years. After this time has passed, the dryer pretty much turns into a collection point. In other words, instead of the moisture absorbing gel beads inside the dryer collecting the incoming moisture, it is now just collecting in the dryer.....just sitting there. The moisture then plays a see-saw game of going back & forth from inside the lines & air springs - struts & back to the compressor. It makes its way back to the compressor, because most systems are designed to dry themselves by blowing air that's already in the system, back through the dryer & compressor. Whats bad about that? What happened to all that moisture that was built up and sitting in the dryer? That's right, its now being forced....by high air pressure....through the compressor! These compressors generally have an estimated 40% duty cycle, which is considered light duty in most cases. They are designed from the factory to run bone dry and will be permanently damaged from ANY moisture. What makes these facts even worse? If an air compressor produces moisture normally anyway, what does it do when it has to run 2-10 times more because of a leak? Answer: Its going to make 2-10 times more moisture than it would normally! In other words, even if you spend $400-$900(not including labor) for another air suspension compressor, the moisture that has collected in the rest of the system all those years, that's still in there.....will quickly attack and overwhelm the new dryer and then damage the replacement compressor!
How long the replacement compressor lasts greatly depends on 2 things:
1: How much it has to run = If the leak(s) in the system was repaired. If the leak(s) were repaired, you may have a chance. If not, the 40% duty cycle compressor that's made to run 2-10 times more than it was designed, will continue to run constantly until the small plastic parts(all of them have 'em) inside them start to melt. Running constantly is also hard on bearings and even armatures, due to the increased amperage draw from swollen(from moisture) parts(rings) inside.
2: How much moisture was in the system. Over the years, we've experienced new $500+ factory compressors damaged to the point of not working at all, in less than 1 months use....due to excessive moisture in the system alone!
One reason air suspension problems seem to show their ugly heads when it gets cold, is because the rolling lobe type air springs used on these vehicles get harder and less pliable the colder it gets. These air springs are only 2mm thick and can't seal themselves as effectively when the rubber is hard(cold).
With all this being said, our recommendation would be to do away with the air suspension system completely and do an Air Suspension Conversion Kit on your vehicle. Its a simple, straight forward repair and is the ONLY way that you'll be able to rely on an aging Air Suspension equipped vehicle.