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Air Compressor question

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  • Air Compressor question

    I have a Harbor Freight 2 hp-8 gallon air compressor model # 40400.
    I bought it two years ago and have used it a lot in these two years. It has worked great in every occasion (nailing, painting, or dusting).
    I figure after two years of use I should change the oil in it. However, the instructional booklet does not indicate which oil or how much. It only indicates to change the oil every 500 hours.
    Does anybody know how much oil it takes and what kind? (20 ounce's of 30 weight non-detergent, special air compressor oil, etc.)
    Also, do I remove the hex nut on the meter side to drain the oil? Or do I remove the oil sight? (These looks like it would be messy and affords a high risk of leakage if the seal is damaged)
    Or have I missed the oil drain plug?
    Thanks in advance for any input!!

  • #2
    I doubt if you really need to change the oil after only two years. In order to reach 500 hrs in that period of time, your compressor would have to have averaged about 42 minutes of run time each and every day.

    Any auto supply store should have air compressor oil if you still want to change it.
    I decided to change calling the bathroom the "John" and renamed it the "Jim". I feel so much better saying I went to the Jim this morning.


    • #3
      I agree with Dave, I doubt if it needs changed yet. You might also check at a Farm Supply Store. Most of them have Air Compressor Oil also.

      As far as draining the oil, I doubt if the sight glass is removed to get the oil out. It should have a plug you take out to drian the oil.


      • #4
        My local Walmart also sells compressor oil (CH brand).

        As far as draining, you should have a pipe plug at some point low on the crankcase. You definitly do NOT remove the sightglass!

        I agree with Dave and Woodrat, about the time being a little short on changing the oil. Unless of course you see that it is quite dirty, which it shouldn't be. Heck, I had a compressor for well over ten years and I think I only changed the oil twice in all that time. Then it was only because I felt quilty about it. As I recall the oil wasn't dirty on either occasion. So, I'd wait another year or so, depending on your use and the environment in which it is running.