The Stovebolt Site Forums The Shop Area The Tool Chest School me on Air Compressor Maintenance

I've been hobby wrenching on cars and trucks on and off for the past 20 years, and I finally got an air compressor. I picked up an old (1963) ~20gal air compressor super cheap. It works great.

What do I need to do for maintenance on this little sucker? I seem to remember people talking about draining them every now and then, and I'm guessing the compressor oil should be changed every now and then.

Drain the water from the tank on a regular basis. Should be a plug or screw tap in the bottom. It wouldn’t hurt to change the oil. May have to suck it out with a turkey baster. Replace the belt. Make sure you have a good inline water filter. I’m sure others will have more.
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Martin is spot on. Depending on where you live, you may drain the tank once a day or once a week. The more you run it, the more you need to drain it. Moisture in the tank is not your friend!

......Safety video....

Wow, I've never even heard of an air compressor blowing up before. Surely it's more common for them to develop pin hole leaks than explode

From your photo it looks like that one has some sort of "unloader" that allows the compressor to spin up to speed without fighting the pressure in the tank. Be sure that is working properly and the motor will last a lot longer.

One of the jobs I had shortly after returning from Southeast Asia was filling and testing CO2 cylinders that carried 2,000 PSI . We had our own hydrostatic testing equipment where a cylinder was placed in an armored pit in the ground and tested with pressurized water. I can recall a couple of tank failures that got pretty dramatic. Like the video states, tanks fail from the inside out, so unless they're tested periodically, there's usually no way to spot a potential problem. Any obvious external damage or rust pitting is cause to discard a tank. Be sure to drill several big holes in any tank you discard to be sure nobody else gats tempted to reuse it.
Jerry

I live in the pacific northwest where it rains a lot and humidity is high during the winter. I drain the entire system every month, did it yesterday in fact. Each drop on your pipe should have a valve too to evacuate the moisture, hopefully any hard piping has slope on it so it can be drained too. A long time friend had his under the floor of his residence, it had been there for 30 years, the compressor started cycling more frequently, so he went under there to see what was going on. The 30 gallon tank was full of water, he never drained it. Petcock was corroded shut. He got a quick lesson that water weighs 8 pounds per gallon when he hauled it out of the crawlspace. On a good note, since it was full of water, it didnt have much volume of compressed air if it let go. Plumbers fill the waste plumbing with water and use very little air to test because if a pipe let go, compressed air and plastic pipe can be shrapnel city.

I plumbed a short 3 ft line into a T on the bottom of my 80 gallon tank. I put an air blaster attachment onto the hose. Every time I go into my shop I give it a quick blast and I shoot all the water out my front door.

Valves, Inlet and exhaust need cleaning ever so often. One valve especially gets dirty can't remember.....

There are automatic valves that can be plumbed into the drain valve too.

Like Fox, I have a tee in the bottom of my 80 gallon tank and I drain it every time I go into the shop. The drain line is big enough that it will hold all of the water on most occasions without it actually sitting in the bottom of the tank. I also change the oil ever year.
I also use to leave it on automatic a lot until I came home after being gone all day and came home to find the small line to the cut off switch had come loose and the compressor had run for sometime from the "feel" of the air.
Yep, sometime we have to learn our lessons the hard way........now I simply cut it off every time I go out the door. That was about 3 years ago so not much harm must have been done. Its still gittin it today!!

Learn from my mistake!!!

depends on use and geography. I use mine regularly, it stays turned on. I have a drain plumbed out of the bottom and drain at least daily. More often if I'm using it constantly during a day of sandblasting or painting. Can't have any water in the system. Just a open till dry/close. Once a week, I turn the compressor off and completely drain tank and all valves at each drop. I drain and replace oil about every 6 mos. inspect the fan belt monthly. I have a 5hp IR 80 gal compressor. The higher the humidity and use, the more important this practice is. I'm in a high humidity area, so I practice it regularly.