Compresssor don't compress no more

[AW10]

My roughly 12 year old Clarke's/Machine Mart compressor doesn't generate more than about 2 bar. All sounds as normal when running but the gauges (before and after the regulator) don't read more than 2 bar. When I shut it off I don't get the usual momentary hiss from an incomplete compressor stroke; it just stops. Drain underneath seals fine. Last time it was used it seemed fine. It's stored in an unheated garage but can't see how that matters. Any ideas?

[GreenV8S]

I guess the compressor has a piston and a couple of one way valves. If either of the one way valves leaked, or the piston wore so badly that it leaked faster than it pumped, then it would stop working.

Hopefully the valves are replaceable.

[Getragdogleg]

Those little Clarke one are sold under a lot of other names too, its quite easy to get parts for them.

I like to pick them up at the scrapyard for a couple of quid and fix them up, its normally the rubber membrane in the automatic pressure switch that goes, it splits and the pressure escapes almost as fast as the head can build it up.

What model is it ?

[AW10]

It's a 1.5 horsepower Ranger 35. Pretty sure I have the manual for it which I seem to recall has the parts diagram.