I have been rebuilding Hitachi nalers for about 2 years now and this one has me stumped. It works fine if you single shoot it. If you hold the trigger and try to bounce shoot the nails, the driver will not...
The roofers that frequent my shop want their nailers to work like machine guns. Here is what I do to make the hitachi 45 nail fast. Remove the cylinder and sand the fine scratches where orings meet cylinder. I use a rubber slug with a small bolt through the center. The rubber slug fits snuggly into the cylinder and the bolt into chuck of drill. Turn the cylinder with the drill while holding fine sandpaper against the scratches untill smooth. remove the nose from body and replace the sheet (part # 877125) and the bumper. If the sheet fits loose on the driver and the bumper has cuts or missing pieces, the driver will not return with full force. also the oring on the piston should not be too tight. Just snug enough to hold the weight of the piston. While nose piece is off check the air passage to feed piston for trash, use a small wire and push through to make sure. Make sure the orings on the feed piston fit snug. Actually push the feed piston by hand in the nose piece to make sure the three orings fit snugly. A loose feed piston will reduce nailing speed. Finally replace the boot on the firing pin. If the boot is blown off its seat with use replace the firing pin. A loose firing pin will waste air and lower pressure reducing nailing speed. Good luck
Dec 01, 2008 |
Hitachi NV45AB2S Coil Roofing Nailer