I have a Blue Hawk model 0300812 air compressor purchased several years ago from Lowe's. Sometimes, but not always, I get air leaking from here:

enter image description here

It doesn't leak from around the threads, as one might imagine, but instead through what seems to be a pin-hole in the cap of the screw. This is an intermittent leak. When it leaks, it will leak constantly for several months, but then it will go for months without leaking at all.

According to the documentation I found that seems to be part #8, the Check Valve. It's definitely not #10 the Relief Valve.

enter image description here

  • Have I identified this part correctly?
  • Can I simply pull what appears to be a nut out of the top of the check valve and replace it with one from the parts bin?
  • If I have to replace the whole check valve, is this a fairly standard compressor part, or do I have to find one specifically for this model or at least Blue Hawk brand?

1 Answer 1


That is indeed a check valve and it prevents pressure in the tank from leaking out through the compressor when it's not running. This is nothing specific to the model of compressor you have and you can likely find a suitable replacement for the whole thing at a dealer that sells parts for compressors. The key thing will be get one that has the correct threads to mate up with your tank and the input hose.

Remove this one and take it with you when shopping for a replacement.

  • Now the fun part: Finding a place that sells these types of things... was that subtle enough? :D
    – FreeMan
    Oct 3, 2020 at 22:13
  • Heh... just realized my office is 1 block from a pipe & valve supply company. Unfortunately, I haven't been to the office since mid-March... :/
    – FreeMan
    Oct 3, 2020 at 22:28
  • 1
    I'd dismantle the valve and see if the problem is something simple like a metal shaving or other piece of crud preventing a good seal B4 replacing it altogether. You can't make it worse, righ
    – Kyle B
    Oct 4, 2020 at 1:01

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