Re: Airing Down

"Bob La Londe"  wrote in message news:v3ksno$3vlg0$1@dont-email.me...
The other day I went out to rescue somebody stuck in the sand.
---------------------------
I did all my off road playing on a dirt bike I could (and often did) manhandle out of mudholes.
An uncle in Colorado showed me how he had modified an old A/C compressor pump into an engine driven air pump to reinflate the tires.
https://www.garagejournal.com/forum/threads/car-a-c-compressor-used-as-an-air-compressor.361016/
"A car compressor like an old York used on AMCs, Fords, etc. are piston positive displacement pumps with a sump containing oil. They will work as an air compressor. Newer swash plate type compressors or rotary compressors circulate oil and are not as good as an air compressor."
If you put tire valve male and female fittings on an air hose you could deflate and reinflate from inside the cab. The thread is close enough to 5/16-32, a standard if uncommon tap size.
You are suggesting a pressure relief valve. I suspect a commercial valve would need the spring changed to a softer one to make adjustment less fussy. They aren't hard to make, the used control valve I bought for my tractor bucket loader had a fixed setting relief that I modified to be user-adjustable according to an added gauge. The actuator plunger consisted of a tap bolt with the hex head turned round and grooved for an O ring, which sealed the low pressure drain side. It compresses a spring that presses the original valve disk against the orifice. Originally the relief pressure had been set with shims.
Usually I make thumbscrews and control knobs from knurled aluminum. Recently I tried knurling acetal which turned out very well, clean and sharp.
I mentioned converting a pull ring pressure relief to a cam handle. The cam lever is a sheet aluminum rectangle bent into a channel over stock a little thicker than the valve stem diameter, and mostly filed to a rounded cam profile to lift the valve and hold it open.