Tools, Sharpening and Power Machinery - Just Acquired Vintage 1972 Air Compressor—Never Turns Off!

I recently purchased a very nice ~22 gallon V-Twin air compressor unit marketed by Montgomery Ward from a local garage sale. The unit is marked as having been manufactured in 1972, by Kargard Industries in Marinette, Wisconsin. I have very little information about the compressor beyond this, as most of the labeling on it is worn off.

The old hunk of steel and iron works far better than my previous compressor, an oil-less Campbell-Hausfield (and far quieter too), however it makes me nervous in that it never shuts off—all modern compressors I have used shut off at a certain pressure. It has a pressure gauge, although it does not work, however other than a manual pressure release valve, I cannot determine how it is releasing excess pressure.

Any thoughts? I don't want this thing to explode on me, however it looks to be of fairly decent quality, so I imagine some sort of provision for pressure overload must be built in, though I'd like to determine exactly what that provision is, and determine whether or not it is working as it should.

Welcome to the forums! With that much age on it you should consider changing the overpressure valve, and the pressure switch. The pressure switch is probably at fault, or the pitot tube from the compressor to the switch could be clogged. Let us know how that goes.

Chandler—thank you for the response. Can you tell me, in general, where I might find the over-pressure switch and over-pressure valve? What do they look like? Thanks again.

The over pressure valve is usually available where compressor attachments are sold. Either at a big box or hardware store. Your pressure switch has a cover. Take it off and take it with you to the store and buy an exact duplicate based on the information inside the cover. You may want to post a couple of pictures on a site such as photobucket.com and copy/paste the HTML code to your reply post.
That way we can see what you have.