Anyone know anything about compressors?

[eddypeck]

Total newbie and probably dumb question, but I bought a little 2hp 50 litre compressor a little while back. Paid £100 but I think it might be broke. Hopefully it can be fixed easy enough, or perhaps I'm just stupid and missing something obvious.

It runs for quite a while then eventually cuts out, which I'd expect as 50 litres is quite a lot to fill. But it only gets up to about 1.5 bar pressure.

This is the model:






It seems to constantly leak air from under here:


the air seems to come out from around where the wires go in underneath.

and there's this little thing which I presume is some kind of pressure valve that has 8 bar stamped on it.



Which I guess could be the problem. Can this turn? is this how you adjust the pressure, is it a simple case of setting it up or is this valve likely to be seized?

[Nate]

Yes, it sound like the thing that turns it of when it has reached pressure is goosed. Try someone like machine mart spares dept for a replacement, should be reasonably standard.

For a quick bodge, try pulling and pushing the on off switch a few times. Mine can be a bit sticky, and leaks sometimes. Doing this "fixes" it

[Blueshark]

Is there no pressure gauge under the switch?, beside it there useally is an adjusting valve (mine has) to adjust working pressure.

I think I see it under the picture of the switch.

Joost

[eddypeck]

Yes there's a gauge but nothing that appears to be adjustable.







If I'm correct this is the gauge that tells me the pressure of the tank, I think there should be another bit that's possibly been removed. A regulator and a second gauge to set the pressure of the output.

As you can see the gauge is very hard to see due to over-spray, the whole switch unit gauges and the missing regulator and moisture trap are all readily available on eBay so I think I'll just replace the whole lot.

[james butler]

yeah dont mess with this!
the black box on the compressor regulates the pressure by switching off when the correct pressure is reached. these units are set to one pressure and cannot easily be adjusted. it is far easier and SAFER to buy a new black box unit you pointed out which aren't expensive and replace it.
i had a compressor with a faulty pressure unit once and when it reached correct pressure would cut out and loose all pressure before restarting.
i took it apart and there are setting screws for cut out pressure and cut in pressure.
i adjusted the cut in pressure screw which resulted in the motor constantly running and over-pressurising the tank and then blew the safety plug out of the end of it. since then Ive vowed never to mess with these kind of things again considering the cost of getting it repaired isn't actually that bad.

[james butler]

one thing woth doing though thinking about it, the brass thing behind the hose coupler is a pressure relief valve, give a tug on this to test the spring inside, if the spring is duff then this valve could be whats leaking your air out.