Craftsman - clean oil in the water

by Archie
(Vancouver, Canada)

30 gallon, oiled, two cylinder, belt-drive. 200 hours on it to date. I like to run the machine for a couple of seconds on start-up to blow any residual water out Yesterday I noticed clean oil in the water. Should I be worried?

Bill says....

All oil lubed compressors put compressor lube oil into the compressed air stream.

If you've just noticed this happening, that suggests that you are getting more piston seal blow by, and, also suggests (not surprisingly) that you have wear inside your cylinders.

The amount of oil is something you want to monitor.

That compressor oil is not good for Buna N seals.. sometimes it eats them, so if your air use includes appliances with rubber seals, you'll want to remove that compressor oil before it gets to the seals. (COALESCENT FILTER)

Make sure your oil sump is topped up, and continue to monitor. Too much oil will tell you it's time for a tear down and fix up.



Comments for Craftsman - clean oil in the water

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Jun 20, 2011
Craftsman - clean oil in the water
by: Archie

Thanks, Bill,

Do you think 200 hours is about right for valve or cylinder wear? I'm sort of a newbie when it comes to compressors, but it seems excessive to me.


Over what period has your air compressor seen 200 hours use? I'd change the oil at least once a year if it was my air compressor, more frequently if the compressor gets hard use.

Jun 11, 2011
Air Dryer
by: Daniel


I'm just new to the compressor industry, but from my understanding the first piece of equipment to add would be an air dryer. This removes the water from the air and by default a lot of the oil also. What are your reasons for advising a filter over a dryer?

If you install an air dryer without removing the oil first, you will, depending on the style of dryer, destroy the desiccant media. The typical install for a dryer is a general purpose filter first, a coalescent filter second, and the dryer third. In order to be specific, it is necessary to determine what dryer is to be employed.

General purpose compressed air filters take out free water.They do not do an effective job of removing water vapor, and it is the water vapor in the air that condenses in the lines allowing free water to again be in the air stream to the application.


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919.152810 - Craftsman Compressor motor has shot bearings

by Dave

My Craftsman 919.152810 motor died due to shot bearings. The drive end has a bearing pressed into the cast aluminum pump housing.

I removed the armature from the motor, and was able to move the cast aluminum pump housing far enough to cut the outer race of the bearing in order to get the pump casting off.

Unfortunately, in the process, I cracked the internal motor cooling fan (NOT the external squirrel cage fan), which is molded over a knurled sleeve.

The motor is an A. O. Smith MO-3024.

Do you know of any source for either a replacement motor, or replacement parts?

If I can get the internal fan, I can replace the bearings and get this thing working again as the armature and fields are still in good condition.

Thanks for your help.

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