Impact wrench - weak

[ollie76]

Afternoon folks,

I have a CP7749 that I got used a couple years ago. I tried it out a few days ago for it's first real test and it seems very weak and I'm wondering what I could be doing wrong? I have A-style connectors on 3/8" hose and I set my regulator to 90PSI. It had a hard time removing lug nuts.

All the reviews on this thing are very good so maybe it's due for a rebuild? Are those tune up kits expensive?

 

[Ruger_556]

Regulator needs to be open fully or at least set to tank pressure whatever your compressor will make. 90 psi is the running pressure you want... It takes more than you think to get it.

 

[ollie76]

I did notice the regulator gauge drops significantly when the trigger is pulled. I guess that does make sense.

So you have to jack it up so the gauge drops to around 90 when the trigger is pulled? I believe the compressor cuts out at 120psi so that would be the max I could dial in.

 

[AndrewV]

Is it running at the right cfm's?
And have you oiled it at all?

 

[ollie76]

I have not oiled it......it's been in my box for about 2 years and never used.

 

[GSteg]

You can even dissemble the gun and oil up the vanes to make sure they aren't stuck to the rotor.

You also want 90 psi at the gun's inlet, while holding down the trigger. 90psi at the regulator with no load means you are severely underpowering your gun.

The CP7749 is not a weak gun by any means!

 

[ollie76]

Great tips....I'm a newbie with these things. I will give these tricks a try and see how she goes.

 

[Jswain]

As said, let it have the full 120, put a little air tool oil in it and let it run wide open in F&R for 10 seconds each, then put another 3 drops of oil in and try it on the lug nuts again. If it is still having problems with lug nuts either manually take it apart and clean it, re-assemble & oil it, or some people claim heating marvel mystery oil works as well without having to take apart the tool.

 

[sberry]

That gun has a 4 speed on it? Nice unit, crank it up.

 

[ollie76]

3 speed if I recall correctly, will check it out

 

[evildky]

Chicago Pneumatics are not what you call a premium brand, I wouldn't be surprised to find they are grossly over rated on TQ.

 

[ollie76]

Never asked for an opinion on its quality. Just some advice on operation, thanks.

 

[Ruger_556]

Chicago Pneumatics are not what you call a premium brand, I wouldn't be surprised to find they are grossly over rated on TQ.

Chicago Pneumatic and Central Pneumatic which is who you are probably thinking of are two very different companies. Chicago Pneumatic has been making good tools for a very long time... If anything theirs are underrated.

Open the regulator all the way up and run some air tool oil through it. Should be fine

 

[C96]

I run all my air tools at 125psi at the service point, anything less seems to be a slight disappointment.

 

[Ign]

Oil it! and adjust regulator with gun trigger at WOT

 

[stikman56]

Five things to check if that doesn't help. First, does it have a screen on the inlet? I've seen those things clogged up with teflon tape etc. cutting the air to the tool, and second, it could be losing air ( not getting it all to the motor) due to bad seals, etc. Next is the hammers and anvil where they contact each other. If all that checks out, the end plate on the motor on most wrenches will wear from the rotor contacting it. When they wear a lot they lose major power because the air just slips by the end of the vanes. Is the inlet valve worn on the edges? This causes the valve to move over when you pull the trigger and so what happens is you aren't opening the valve all the way. Those are the 5 major things I have found wrong when power is low on a pneumatic impact.

 

[wild cowboy]

I would strongly recommend going to an auto parts store or wal-mart and pick up some regular Marvel Mystery Oil - it brings air tools that have been sitting around back to factory new performance.

In the shop, we call it "Air tool crack" - lol

and as others have stated, put that regulator on full blast! - all the way open!

 

[Mohawk Dave]

I would strongly recommend going to an auto parts store or wal-mart and pick up some regular Marvel Mystery Oil - it brings air tools that have been sitting around back to factory new performance.

In the shop, we call it "Air tool crack" - lol

and as others have stated, put that regulator on full blast! - all the way open!

THIS!!!! miracle stuff on sitting air tools. Tri Flow kicks *** too.