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Why won't feed plunger advance nails?

Feed plunger of the NV45ab moves toward piston shaft when air supply is attached but won't advance nails after the first one is fired. Have replaced the o-rings. What is the purpose of the two allen set screws located in the exhaust cover. Will they affect pressure to the gun. Don't want to touch them until I know their purpose.

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  • lips0 Jan 25, 2013

    I backed out the two allen set screws in the exhaust cover and the feed plunger mechanism worked. To prove it, I turned the screws (one at a time) all the way back in to the stop point. Each screw blocked the air supply to the feeder assembly. I don't know if there is a correct setting for eac screw but I backed them out to the point where the gun worked correctly. Does anyone know the correct set point for these screws or how they are supposed to be adjusted?



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The two hex head screws on the very top of the head hold the air deflector and attach to the headvalve (the part inside the head with rubber coating, this headvalve has a gasket under that should be check for proper alignment ). Other small screws that look like set screw are only plugs that are removed to install auto control hoses in factory work. These are only plugs so just put them in a few turns with locktite.

Posted on Jan 31, 2013


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SOURCE: DeWalt Frame Nailer 51844 extends firing pin when air hose attach

Check whether the trigger is working properly, and whether the air valve is not leaking.

Posted on Jun 15, 2009

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SOURCE: Dewalt 51488. Air leaks around trigger and won't fire nail.

Go to and download a breakdown of the tool before starting. I would recoment changing all the O rings and make sure that you get a good grease to lube them first. Its not that hard.

Posted on Jul 17, 2009

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1 Answer

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