I found an old 3/8″ Black & Decker pneumatic impact for $5 and decided to pick it up. Its pretty old and, sure enough, when I looked it up online there’s practically no record of its existence. I brought it home, hooked it up, and it works pretty well. There are a few issues though. The first is that the retaining ball has gone missing and it won’t hold a socket on. The second issue is that it is very dirty with lots of old grease packed into the tight spots. Time to fix it. Here’s what I started off with.
The rotor assembly has a slight interference fit with the body of the gun. I found the easiest way to remove it is to hold the body by the handle and strike the front face of the body with a plastic faced hammer. Similar to seating an axe head, the rotor housing doesn’t move as much as the body and slowly comes out.
Once I removed the rotor housing, I started to disassemble it. I flipped it over and ran into a humorous bit. The rotor is held in the bearing by a pan head Phillips screw. Obviously, it works but its funny to run into a cheap screw here.
Anyways, getting the rotor out was the hardest part. After that it comes apart pretty easily. I did run into a couple brittle gaskets. It’s a good idea to put the vanes back in the rotor in the way they came out from what I’ve read online. I don’t know that it matters and mine fell out accidentally anyways.
I recently replaced the pump in my cheap parts washer and used it to clean everything. It’s nice to be able to throw everything in there for a little bit and then wash them off later. Everything was scrubbed, cleaned, dried, and oiled before reassembly. The bearings also go fresh grease.
I noted before that I had some gaskets that needed replacing. Parts aren’t available for it and if they were might not be worth it. So, I grabbed some gasket paper and proceeded to make some replacement gaskets.
To fix the retainer ball, I fished around through some old ratchet parts kits I had and found some pieces that would fit. The ball is the correct diameter and I slowly trimmed a spring down to a good size.
I pressed the ball in to the hole and found that it stayed in. The ball works to retain a socket but is a little stiff. So, it’s not a perfect fix but it’s functional. Besides the square drive is pretty worn and lets the socket wobble around a lot.
I tried it out and found that it broke a nut loose pretty easily that was torqued to 125 ft lb. So, it has some strength to it. I’ll try to use it next time I’m working on my vehicle to see how it does. It’s be nice to have an impact thats smaller and lighter than my 1/2″ one. If I find it to be great I may have to purchase a new 3/8″ impact.