What is a Compressor?
Air suspension needs air to work. For the most basic Motor-home and van systems this may not be on board the vehicle and they are sometimes inflated from a normal tyre inflator (Schrader valve) at a workshop or petrol station.
Those vehicles without on-board air (OBA) generation are very much in the minority. Most systems have a small compressor which generates the air and fills a tank.
The compressor is really a small air pump powered from the vehicles 12v dc electrical supply (usually). the motor turns and pumps the air into a tank (normally) to store a reservoir of pressurised air for immediate use anytime you want. There are systems that generate air directly from the engine but these are in the minority.
Old style compressors are large, heavy, noisy, and unreliable – see below.
Newer technology high quality compressors are very reliable and come with the stainless leader hose pre-fitted and pre-tested – they never leak (unlike the ones at the top), and draw a predictable electrical load (unlike the ones at the top). As a bonus they are also lighter and quieter.
Top spec air installations will often use 2 of these units to ensure tanks are filled quicker, and to reduce the load on each compressor.
Cheaper Firestone units are good compressors, but are often rated at only 7% duty cycle (use it for 7 minutes then leave it for an hour and a half before you use it again!!!), and some are quoted by Firestone as designed for use 2 or 3 times a week. despite being totally unsuited to many custom air installs cheap skate suppliers still insist on using them.
Our compressors are rated at 100% duty cycle at 100 Psi, and go to 200 Psi.
The main cause of compressor failure is clients or suppliers having simply chosen the wrong item for the job. Cheap kits often supply compressors with very low duty cycles (which remarkably can often be less than 10%). This simply wont function for very long in an automotive system. Others are susceptible to damage from moisture or dirt or require the client to fit a hose to the cylinder head in order to install it on the system. Since this is the most likely place for a leak this should be factory fitted and tested to avoid issues for the client. ALL OUR COMPRESSORS HAVE FITTED LEADER HOSES.
Finally – If the pressure switch is fitted directly to the compressor cylinder head – it will fail. Since this is a vital safety device its correct and reliable function is essential to the safety of the system. This can also be the cause of failure of the cheap types of compressor when the switch fails it allows the compressor to run until it dies. Systems have no way of controlling the duty cycle of the compressor so its really essential on most systems to have a 100% duty cycle.