Discovery Suspension Compressor (L318)

WARNING: the compressor does not fail on its own.

It is therefore extremely important to understand the causes of its malfunction before replacing it with a new/reconditioned one to avoid a repeat failure.

The general causes are:

The relay is not replaced and the compressor continues to run until it seizes; always replace the relay.

Even a very small hole in the air spring, in the height adjustment valves or in the system will cause the system to leak and the compressor to activate more than necessary to bring it back to pressure; the larger the hole, the faster the system will discharge. Therefore carefully check that there are no leaks of any kind.

The compressor draws ambient air through an intake pipe that is most often fitted with a filter. If this pipe or this filter are broken, the compressor could draw in debris, dust and water, resulting in internal breakage and corrosion of the piston and cylinder. Therefore check that the pipe and filter are intact and dry inside.