Astro 4980 maybe not working right?

[Frankiej]

I bought me a big nasty 4980 last July. Maybe it's just me not being familiar with big bore hammers, but it seems like maybe it's not working like it should.

Since day one, when I'm using it I have lean every bit of my body weight into it when I have the trigger pulled, otherwise the piston doesn't hammer and it just blows air through. If I'm in any kind of position where I can't put my body weight to it, it's not very usable (on a creeper, etc.). It even starts to blow through without hammering if it gets slightly off center, more of a glancing blow when things get sideways. When I've got it loaded with lots of back pressure and am able to hit the piece perfectly square it seems to hit pretty hard.

I use it at my job as a state department of transportation mechanic, working on lots of dump trucks and large equipment, so we've got a large air compressor that runs multiple large air tools all day. Our air pressure is usually 150 psi or so at the hose, so I wouldn't imagine it would be an air delivery problem.

I was just wondering if everyone's performed like this and maybe it's just me. I've used lots of small bore air hammers, from the cheapy Central Pneumatic all the way up to the Snap On 3050, and none perform this way. My boss has an older Matco hammer, and it has to be loaded with some back pressure before it hits, but it's a fraction of what my Astro requires. Thanks a lot in advance to everyone who replies.

 

[boom10ful]

Are you using .498 shank bits or the smaller shank ones?

 

[Astro_Pneumatic_Tools]

Air hammers (all air hammers) when they are just blowing air it's usually a sign there it's a hang up in the cylinder bore the piston is experiencing.
Off the shelf if one has been sitting for awhile or if it's stored in high humidity this is usually oxidation between the ID of the cylinder and the piston itself. A rubber mallet with the trigger pulled can often free it. Then an application of a liberal amount of air tool oil into the fitting.
If it's hanging up over and over, the cylinder could be scored or that location the piston was sitting in for a long time left a patch of less smooth oxidized surface and it has to wear past that layer, with repeated pneumatic oil and use.
If no improvement THERE, we probably need to look at it and possibly replace a few parts.

 

[Frankiej]

I am using the .498 bits. The Astro 3 piece set that I ordered with it.

I'm not going to be back to work where my 4980 is until Monday, but I'll try checking that the piston slides free. I've never really felt like it hung up, but then again I wasn't really checking for that.

I oil it with air tool oil every time I've used it. 2 to 4 drops. I'll try putting a bit more in it and running it. It also seems like the blowing air problem might be happening more the more I use it.

Thanks for the reply Astro. I really appreciate it. I've got several Astro tools and this is the first time I've felt less than great about any of them.