# Trying to get old Crsftman working



## Intrepidation (Jan 3, 2017)

Greetings!

I have an old Craftsman 919.174811 air compressor I'm trying to get going. I'm not an expert at all with air compressors, in fact this is my first unit I've ever owned!

It was given to me two or three years ago by a friend who was using it for his waste oil furnace but replaced it and asked me if I wanted it. It worked at the time but had no gauges or anything. I brought it home and put it in the corner of the garage with the intent of working on it...just sort of never got got around to it until now.

I bought a pressure gauge for it and a few days ago I went to plug it in and see if it still worked...it didn't.

It has a replacement plug on it, quite old one. I figured maybe its corroded in there. Well the ground and white wires were actually broken inside and not connected to anything! 

Strangely, the black seemed to be connected to the wrong prong. I replaced the plug and wired it according to what it should be. Compressor fires right up, however around 30 PSI the motor seems to sound like its really struggling and it begins to squeak. The first time I ran it it stopped a bit past the 30 mark and wouldn't turn back on. I bled all the air out and turned the switch back on and it came right back on then started doing the same thing. If I open the air bleeder as it gets to 30 PSI and slows down it'll speed back up and sound normal as the pressure is released.

So I guess the first question is what might be the culprit here?

Second question regards the switch. It has no cover and that's all kinds of unsafe. I want to either get a cover for it or replace it with a new switch. The switch says its part #CAC-496 . I cannot find this switch anywhere. It says "Cut-in 75 / Cut-out 100. All I can really seem to find are 70/100 PSI switches . Not sure if those are acceptable replacements. Also, I don't see an unloader valve on mine.

Any help would be appreciated!


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## Intrepidation (Jan 3, 2017)

So a little more research leads me to surmise that maybe the adjustment screw on the compressor is set to cut out at the lower PSI, which I'm guessing is the coil spring/screw assembly.


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## Intrepidation (Jan 3, 2017)

Doesn't see,m to be a post edit feature here, so I'll clarify with another post. Once it gets to about 30 PSI it starts to slow down and squeal, maybe teh belt? I don't know. However it doesn't stop it gets slower and slower until it barely turns. If I turn it off and back on again it still barely turns. Once I let some pressure out it starts turning again. 

I tried turning what looks like an adjuster, but didn't seem to make a difference. 

Looking at photos of similar looking units, there's the main air line and then a second smaller line that goes to the switch. However there's a plug on the pump side and nothing on the switch on mine.


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## Intrepidation (Jan 3, 2017)

I figured it out myself. However, for anyone curious it turned out to be the belt.

Shame it was a waste of time. I discovered that there's water in the tank that''s been in there for who knows how long. The tank is almost certainly compromised. I did run it with the tightened belt. It went to about 60 PSI and was still going when I shut it off and released the air.


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## motormonkey (Jul 10, 2016)

The tank might be safe and salvageable. It's not too hard to do a hydrostatic pressure test on it and find out.


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