Pneumatic Needle Scaler Rebuild

[Jland]

Anybody ever rebuild one of these??? Seems to have a total of 6 internal parts... I watched a video where a guy just sanded off a couple of parts. Mine just doesn’t hit hard anymore

 

[Al Borland]

Yep. Not much to them. Clean the valve, piston and bore. Replace the spring and the needle set. Done.
Spring is a big part of how it hits, and they weaken/break. Make sure to lube it. DO NOT put oil down the needles.

 

[ultgar]

Here's the schematic for the Facom ones I sell...nice that they offer the rebuild parts.

 

[Bitter]

It's roughly a little air hammer in there, is it consuming the same volume of air and not hitting the needles as hard or is it sucking less air and not hitting the needles as hard? If it's consuming less air and not hitting as hard check the air inlet, throttle valve, and diaphragm assembly for blockages, also check that the ports in the cylinder are clear and that the piston is able to move smoothly back and forth without binding. If it's consuming the usual amount of air but not hitting hard I'd be more suspect of the piston binding being the issue, likely due to lack of lube in the cylinder and corrosion from sitting between uses without protective lube. Sometimes some light oil down the bore and using the tool for a bit will work it free, sometimes it needs mechanical intervention.

I know having a lot of parts can be intimidating, when I'm breaking down a tool I try to work in sections if possible. Start at one area and work on that, then assemble it, test it, work on the next part, assemble/test, etc. I like to start at the air inlet and work my way forward because the air inlet and throttling is usually the most simple. Good luck with the repairs!

Tip: I've found from my own use of needle scalers that rounded tips on the needles don't work as well, I'll take mine to the grinder and flatten them back out to get that 'new needle bite' back.