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by Jeff Chubb
(Palmyra, PA USA)
Mech Power M90002- my base of pressure switch (cast metal) broke off.

All components of the switch were in working order, I just need the base metal part. the gauges and switch are all good . is a base part available? if not, is the entire assembly available?
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Mech Power M90002 pressure switch
I doubt if you’ll find an OEM pressure switch, though I expect you will find after market switches that will fit.
I’m curious as to how the base broke? I had one go on another compressor, the result of an over-tightened fitting or a flaw in the white metal.
See https://about-air-compressors.com/buying-a-compressor-pressure-switch.html for some guidance in finding a new switch if you need it.
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Pressure switch
Looking at other pix of this machine, it looks like the switch itself is not broken, but a pipe broke off in it.
That broken piece can be removed, but then where did it break *from*? I think the tank – is that piece removable? Then all you’d need is a short-ish piece of 1/4 inch pipe, from the look of it.
Maybe send a pic of what it broke from, if I’m way off-base?
I found this replacement switch on Amazon
Hi Esprit, do you have an Amazon link to this part?
I need the copper line from the tank to the pressure switch. I am retired HVAV pipefitter and I’m unfamiliar with the tubing and size fittings to make the new part. It appears to be metric equivalent of 1/4 ” flare fitting on one end and compression on the other end. The tubing was not soft drawn copper.
Perhaps the information on these pages will help: https://about-air-compressors.com/fitting/ and https://about-air-compressors.com/metric-fittings/. Regardless of what was there before, as long as the air path is no smaller in diameter, and you can attach the pipe to both ends, use any material that works. I often suggest soft copper as replacement air lines, and this may work for you as well, though bending it tightly will often result in a kink so care must be taken. The unloader line – the line I believe you refer to – runs between the pressure switch and the tank fitting which normally has an integral… Read more »
I tried. I even bought a flaring tool , but thanks for the links.
James, were able able to source soft copper metric (8mm ?) tube?
Or were you trying to reuse the hard copper?
Maybe tell or send pix of what broke where??
Or have you already thrown up your hands in disgust and bought a new compressor?
I conducted an internet search for the fittings and tubing . It was frustrating and time consuming . I was hoping I could find the whole thing somewhere, but have been busy with other projects here. Here’s a photo of the connection I need to make. Working in the piping industry for many years I never saw such a crazy set up. Compression on the top, flare on the bottom . Also the offset TOWARD the tank on flare side is weird.
Yeah, that looks like they had some excess parts laying around and made this thing from them. Given that, chances of finding a direct replacement are slim to none. I have one very similar, but the check valve in mounted on a horizontal axis of the tank, so it faces the unloader valve more or less directly. Anyway, absent any better info on the parts, it may be best to remove that check valve, verify the threads (could be BSP or NPT – probably not metric) and just replace it with something more suitable. Ditto the pressure switch, if and… Read more »