Pneumatic Paint Shaker Repair

[Richard D]

Mine stopped working. Used to be it would go if you gave it a bump with the palm of your hand, but no more. Is there a common problem that causes this? It moves freely when there's no air but stays stuck in the middle of it's travel under pressure.

 

[cvairwerks]

Have you given it a shot of lubrication via the air inlet?

 

[Richard D]

Yes I almost always oil my air tools every use, probably overkill. It has been greased frequently, not constantly, maybe that's the issue? I don't use it much and it is in a climate controlled shop.

 

[rlitman]

Mine has an in-line lubricator, so it gets heavily oiled. When mine failed, it was a broken hose.

There's a short section of flexible hose connecting the inlet to the piston. The vinyl hose in mine was flexing severely with each stroke and eventually cracked. At that point it hissed and shook more slowly, but I ignored it until it stopped shaking entirely when a chunk of hose blew out.

My fix was to use a piece of hose cut out of a coil hose. Instead of using a short section that just bent in the middle, I put in a full loop circle of hose to spread the bending around, and it's been good ever since and no more hissing.

 

[Lightning rod]

in order for the piston to move back and forth, there must be a valve of some sort to reverse the direction of the air flow on the piston.
It's either broken or stuck with debris or something is clogged.
Assuming it's a HF model, inspect the parts against the parts diagram

https://manuals.harborfreight.com/manuals/94000-94999/94605.pdf

For example, part 11 on this diagram is may not be functioning correctly.

 

[Richard D]

I bet it is either one of those issues, thanks. I'll pull mine off the wall and check it out.

 

[Richard D]

New hose didn't do the trick. When I open the valve air is escaping from some small holes drilled in the cylinder body, #19 in the diagram. I have not opened the cylinder for inspection yet.

 

[rlitman]

New hose didn't do the trick. When I apply air I can still hear a hiss. I have not opened the valve for inspection yet.

The reciprocating piston works just like the one in an air hammer. It's usually easiest to inject a penetrating oil into it to loosen up whatever got stuck in there and see if some airflow clears it up after that.

 

[Richard D]

Would I put penetrant in the air fitting?

 

[rlitman]

Would I put penetrant in the air fitting?

Yep. Just like with any air tool. Shoot the oil in the inlet and let the air carry it through and out.

 

[Richard D]

Tried that, didn't fix it right away, so I put in some more and letting it soak.

 

[barks]

Tried that, didn't fix it right away, so I put in some more and letting it soak.

Now a year later. Have exact same issue. Did you identify a fix?

 

[The Cobbler]

I replaced the check valve and some o rings on mine to fix the issue. Astro pnuenmatic were great to deal with for parts

 

[Richard D]

Never did fix mine.

 

[barks]

How did you "break loose" the screw on top of the piston? thanks.

 

[Richard D]

Was a year ago, I can't remember.