Question about Hitachi NV45AB2 Roofing Coil Nailer

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Hello... I have a Hitachi NV45AB2 Roof Nailer. I have just completed a service on this unit with the 18001 O-Ring Kit. Everything looked good after cleaning and inspection. Problem is that I now have air leaking out of the nose at the driver hole. Any suggestions would be appreciated.

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You can first try "tapping" on the cap with a soft hammer while air plugged in to seat the cylinder and if the air doesn't go away then you might have pinched an o ring while assembling. Also while assembling did you lube the o rings so that they slide and don't roll out of the grooves. Let me know if you need more assistance.

Posted on Apr 05, 2011


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Posted on Jan 02, 2017


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1 Answer

Air slow to build pressure after the trigger is pulled not sinking nails completely

Tear the tool down and install #18001 Rebuild kit. Just because the O-rings look good doesn't mean they are not worn.
Also make sure you grease the orings with the grease provided in the kit.
The entire cylinder has to move up and down in this gun so it is important it is clean & lubricated.

Mar 06, 2015 | Hitachi NV45AB2 Roofing Coil Nailer

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Hitachi nv45ab2 is leaking out the back orings look good 1 year old

Remove the head and check that the cylinder moves down and then up again. If the cylinder is stuck stuck down, remove outer ring and pull out the cylinder. Check for grit and or scratches where the orings make contact. If scratched, remove with fine sandpaper, lube and reinstall. Check that the cylinder is in the upper position before you install the head. If the cylinder moves down then up again, check headvalve seal (rubber seal in the head) for cracks or the rubber has become loose and spins. If loose reseal with RTV. If cracked, replace with generic or factory part. Good luck

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I have a craftsman roof nailer with plastic cover for nails broken where can i get one to fit

Best place for replacement parts is the address below.
Ez to order from and usually only takes 10 to 14 days to get the parts. Click on Hitachi logo then select coil nailers, then your model number. For local parts, look in the yellow page directory for fasteners. Fastener companies that sell nails and other supplies to contractors also have parts for Hitachi nailers. Check with several. Some will even repair the nailer for you if you buy nails from them.
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Sep 01, 2011 | Hitachi NV45AB2 78Inch to 134Inch Roofing...

1 Answer

Need manual for Hitachi NV45AB2 coil nailer

go to "" and you can download the manual you are looking for. Let me know if you have trouble or need more assistance.

May 06, 2011 | Hitachi NV45AB2 Roofing Coil Nailer

1 Answer

Hitachi roofing nailer leaks air out the back after falling off roof, I have 5 of them all with the same problem. any ideas?

SOLVED! I replaced all the o rings put it together and air jus blew out the exhaust port. I made the mistake of pushing Piston plunger cylinder into the gun till it seated. this left a gap between the head and cylinder. I took the gun apart, removed the cylinder, an reinstalled it only far enough to seat past the o ring gasket. I then installed the head and let the head seat the cylinder as I tightened the screws. this worked on two guns with the same problem. Jn 3:17

Dec 11, 2010 | Hitachi NV45AB2 Roofing Coil Nailer

1 Answer

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could be feed pawl problems e.g. broken spring, restricted movement or the piston is not retracting fully, either way I would probably try and rebuild (new o rings, thorough cleaning) this tool. You can buy a replacement o ring kit from you will need to give them your model number for this kit. Let me know if you need more help.

Dec 27, 2009 | Hitachi NV45AB2 Roofing Coil Nailer

1 Answer

NV45AB2 worked great a year ago.hooked it up last week and it only shoots the nail 1/4 inch in a piece of wood and it wont advance the next nail.My framing nailer works so the hose presure is good.

if you havent used in a year the o rings could be dry and you can try and lubricate them, but sounds like it needs them replaced. You can try going to and buying an o ring rebuild kit from them. It contains all the needed parts except for the grease to lube the o rings. Let me know if you need more help

Dec 23, 2009 | Hitachi NV45AB2 Roofing Coil Nailer

1 Answer

Year of Manfacture for Hitachi NV45AB2 Coil Nailer Serial Number 341889.. Thanks, Marty

on hitachi air nailers the first number is the month and the second is the year , the only confusion might be if the nailer is older than ten yrs( the nv45ab2 has only been out about 4 yrs) so your roofer was made in march of 04

Nov 20, 2009 | Hitachi NV45AB2 Roofing Coil Nailer

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