Tools, Sharpening and Power Machinery - I need help with this craftsman piece of junk air compressor. :(

Ok first off, please dont ever buy a craftsman air compressor. JUNK!

Model #: 919.165612 (Click here for sears parts direct link) (http://www.searspartsdirect.com/partsdirect/getSubComp.pd?modelNumber=919165612&productCategoryId=0703000&brandId=0247&modelName=AIR-COMPRESSOR&diagramPageId=00001&componentDescription=COMPRESSOR&documentId=50023095&blt=06)


Ok onto my issue. Out of the blue my air compressor started leaking by itself. It would charge up to the set pressure, and the switch would turn off the compressor, it would bleed out till it got to the lowest pressure setting, turn the compressor back on and recharge, repeat non-stop.

I narrowed it down to the brass L fitting in the pressure switch. You have an air line that comes from the tank, into this brass fitting, then there is a tiny piece of straight metal in a plastic piece inside this L fitting, the switch presses against this to relieve pressure when the compressor turns off. Or at least I'm thinking thats how it works. Anyways, that piece is constantly being pressed on so it bleeds air out non-stop when the compressor is off. I have ordered two replacement units from Sears parts direct: Pressure switch assembly, Part #D20596 | CRAFTSMAN AIR-COMPRESSOR Model # 919165612 | Compressor | SearsPartsDirect.com (http://www.searspartsdirect.com/partsdirect/showPart.pd?partNumber=Z-D20596&productGroupId=0009&supplierId=919&brandId=x&documentId=50023095&keySuffixId=NA&modelNumber=x&keyId=016&pageId=00001&productTypeId=x&searchModelNumber=919165612&subCompDesc=Compressor&brandDesc=CRAFTSMAN&modelDesc=AIR-COMPRESSOR&blt=11)

I've installed both new replacements and they both do the same thing as the 3rd original unit. What the heck could be causing this? :( Sears has 0 technical support so I'm pretty much fubar'd.

First off I disagree that what you bought can be considered junk.
For whatever reason, you bought an inexpensive compressor that doesn't meet your needs.
Most of this type of unit will last a reasonable amount of time if used according to the instructions.
I am unsure what yours is rated at but many like this have a very short duty cycle and are easy to overheat.
There is a bit of info here (http://forum.doityourself.com/tools-sharpening-power-machinery/131654-air-compressor-information.html) on this.

Your problem is likely the check valve which is item number 12 on the diagram.
Try taking it apart and cleaning it.

While I can't speak for your particular compressor, I have a craftsman compressor that I bought new 25+ yrs ago. For the most part it has always worked flawlessly. When I have had problems with it, they were directly related to being transported from job to job and getting bumped around in the work van.

Check what Greg suggested and also check all the fittings to make sure they are lined up and snug.

I agree, it sounds like the check valve. I had to replace one on my 28 year old Craftsman compressor a couple of years ago. Same problem.

At least you can get parts.

Man, I've tried everyone and anyone in Sears, Craftsman etc. All I wanted to know is what the proper connector size is for the hose to Compressor, 3/8 or 1/4 or what. I've got a picture and no for the Snap Link connector E100307 but they can't tell me what the actual connector measures. I mean if you wanted an elbow for plumbing, you would say 1/2 copper or 3/4 tee.. etc. I want to buy a rubber hose to replace the cheap plastic they give with the compressor, and I have a vendor, but I can't order unless I'm sure it will fit. It's a 125 PSI Thanks in anticipation for any and all help Tom

Welcome to the forums! It is most likely a 3/8" hose. I personally like the internally braided 1/4" hose as it is more flexible in winter and stronger. However, it still uses the 3/8" fitting.

Unless I'm mistaken, all the air hoses have the same size female thread. I have mostly 3/8" but do have a section or two of the 1/4" There are a couple of different style connectors but most places only stock the type of disconnect that most everyone uses.

One way to resolve your problem is not to use Sears Replacement parts.

Air compressor parts shares some common parts with home water pump set up's.

You can usually go to any outlet that sells pressure switches for a home water pump and set up the switch to turn on and off at what ever pressure you wish.

There is usually a valve that takes the pressure off the head of the compressor - a one way valve that allows the air compressor to pump up to the required pressure and then shut off.

Once it is off, the one way valve will remove all pressure from against the cylinder of the compressor and will not let the air pressure back feed.

When air consumption goes below the required amount, the compressor will come back on - with no pressure in the cylinder, which will allow the motor to run with less resistance then if it still had 90 PSI against it.

A air hose is a air hose. Just as plumbing is plumbing.

If you want a air hose, look in Harbor Freight and Salvage.

They have a online store.

Buy what ever air line you want and go to the hardware store and buy what ever adapters to go up to 3/8 inch or down to 1/4 inch to connect it to the compressor.

If you use air tools that requires a large amount of air, I would suggest that you use a P type connector. A P type is a mechanic's type connector and is sold in most Sears and Lowes stores. It has a larger hole in the center of the connector and allows more air to flow to the hose which supplies more air to the tool which gives it more torque.

Just to clarify, the pressure control for an air compressors has an air bleeder that removes pressure in the compressor head each time the compressor stops.
The check valve allows the tank to remain pressurized and pressure against the pump to bleed off.

The most common fitting size for home compressors is 1/4" pipe thread.
It is common to find 3/8" and even 1/2" ID hoses with 1/4" fittings.