Fixing a problem with my airbrush compressor

My airbrush compressor, an unbranded (although the pressure gauge has Sparmax written on it) TC-501C bought in 2008, recently developed a fault. When switched on it kept running after the set pressure had been reached rather than stopping automatically as it should. I checked the joints for leaks with soapy water, but found none so I started a thread on the Britmodeller forum (plastic kit modellers are far more likely to use airbrushes than railway modellers) asking for help. Someone replied suggesting that the pressure switch might have failed and advised me to contact air-craft.net for further advice and spares. This I did, and the helpful Martin agreed that it would be said switch, which had either failed or been blocked by debris. So, I removed the outer casing from the compressor, firstly by unscrewing the feet then undoing four screws in the base and disconnecting the on/off switch. Then the pressure switch, which is protected by a rubber cover and some heatshrink, could be unscrewed with a big-ish adjustable spanner. It can be seen in the photo below, with the rubber cover pulled back;

Note the exposed wires, these are mains leads so the unit needs to be unplugged whilst doing this!

I also removed the L-connector, and both connector and switch were cleaned out with cotton buds and toothpicks.

This is the switch, note the black crud and dirty water inside;

I then reassembled the switch and connector, with the switch sitting at 180 degrees to its original position as I found I got a better air seal that way;

I refitted the on/off switch and tested the unit, and I'm pleased to say that the pressure switch is now working as it should. I have however ordered a replacement from air-craft as I'm sure that I'll need it one day.

And here's the reassembled compressor;

With thanks to little-cars on the Britmodeller forum, and Martin at air-craft.net (usual disclaimer applies).

Paul.