HOW TO REBUILD A JENNY/ EMGLO Air compressor pump

Today we’re going to rebuild a K/KU pump for Jenny. Also known as Emglo and some models of DeWalt. The heads are identical across the K pumps, G pumps and very similar on the W pumps.

Start with the intake valve, which is a K145. We have the head right here. This is all prepped, cleaned and sandblasted. It’s important to polish these little surfaces down, make sure they’re nice and flat inside here. The intake side has a larger bore. We’re going to take one of these valve disks, drop it right in there. There’s a kind of cone shape to the spring. We want the small side down towards the bottom of the disc. That’s going to keep it from threading out of the valve seat and ending up inside of the head. You’ll notice on the C-clip there is a sharp edge and a slightly dull edge. You want the sharp edge facing up and the dull edge facing down. Make sure it seats all the way. Get yourself a nice pokey pokey tool. Something to make note of is there’s a side with the dimple. The dimple side must go down.

Next we will install a discharge valve. It’s the one with the smaller bore. Just like the intake, we take a K146 which has a heavier spring and install everything in the same orientation. The smaller side in, the dimple side down, and again with the c clip sharp side up. Once you get the snap ring seated, you’ll want to flip it over and give it a nice little hokey pokey. Make sure that the valve moves up and down semi freely. You’re going to feel some good spring pressure and that’s it.

Over here, we’re going to work on the unloader. The unloader kit comes with parts to do both the new style and the old style head. If you have the new style, which is what we have right here, you throw this little washer away. What we want to do is take this o-ring that’s nice and dry and put some o-ring lube on it. Just a little dab will do. Smear it all over there and make sure it gets all over. Put the spring on and drop it right in. Make sure it plunges up and down and put that cap right back on there. These Jenny/Emglo or DeWalt compressors are very common on contractor units, fire sprinkler units and light industrial and commercial compressors. We carry components for complete rebuilds on these and most other major manufacturers.

If you need help with your air compressor, contact us in Portland, Oregon. We provide air compressor parts, service and installation. You can reach us at (503)674-2744 or contact us online.


Dear valued customers,

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