20 Most Recent Hitachi NV45AB2 Roofing Coil Nailer - Page 2 Questions & Answers

The feeder pin used by hitachi has a shoulder on one side and a rubber washer /retainer on the other. There is only one groove and the retainer fills the groove and if the correct pin and spring, no extra room to fit an exstra retainer unless the shoulder is worn so bad that the pin is falling thru the plunger. I have seen a lot of creative ways that owners use to hold the pin in place due to lost rubber retainer or lost pin. I also see many guns that have installed a retainer pin from porter cable which has two grooves (one on each side of the pin and no shoulder ). Porter cable pin works fine and fits perfect. Good luck

Remove the 3mm roll pin holding the trigger in place and set aside the trigger plunger (white plastic plunger should have an oring on groove). Remove the fitting that holds the trigger plunger and replace vinyl ball #875645 or check for debris under ball. Good luck with your repair.

Replace the trigger

If air is leaking from the trigger, check vinyl ball and oring on the white plastic firing pin. If air seems to leak from the plunger just in front of the trigger (with air connected and nails removed move plunger with finger and listen for change in sound), remove the head and pull out the cylinder. The outer oring to the plate around the cylinder is bad, however, clean the cylinder and lube with white grease. Good luck

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

Cylinder guide fits very snuggly into cylinder and generally does not need to be removed unless visually broken. If you have a leak and suspect the orings under the guide, re-post a question. If however you want to pull anyway, I use one arm of a large two arm puller. Remove the outer ring, pull out the cylinder, then gently tap the under side of the guide with the lip of the single arm. Move the arm from one side to the other and it will come right out. Second method is to remove lower half of the gun and push out with rod or hardwood dowel. I have remove many by tapping up with lip of puller and have not damaged any. This part is quite strong, however have not ever needed to replace the orings under this part. Good luck

The nail guide is held on by a pin with a rubber cap on top of it. If you remove the cap the pin will slide out and the guide will come off. You can go to www.ereplacementparts.com and do a search on your model number to see a good breakdown of your gun and the parts we're talking about.

Air leaking around the trigger area could be caused by vinyl ball / gasket under trigger valve bushing or orings within the gun. Easy test, remove nails and connect air (assuming that air is now leaking around the trigger area). Depressing the trigger stops the leak, replace vinyl ball. Depressing trigger does not stop leak, move plunger b (plunger B, small shaft under bubber bushing next to the trigger valve) with your finger in then out to determine if air leak changes tone. If air leak changes sound or tone, then air is leaking past orings of the cylinder guide and/or cylinder plate and/ or the cylinder itself is scratched by debris where the orings make contact. Pull out the cylinder and examine the contact areas. If scratched, use 300 grit paper to smooth, if smooth, however, suspect the orings of cylinder guide (or cylinder guide is cracked). The cylinder guide is difficult to remove and install without causing damage to guide or cutting new orings when installing. Do not remove the guide unless all the other options have been checked. One last bit if information, I have noticed that some guns will leak air if the orings on the feeder piston do not fit snuggly. Make sure that leaking sound is not coming from feeder area (remove the basket and feeder/feeder pin/spring and pull out the feed piston, making sure that the largest oring is making good contact within the cylinder). Good luck with repair.

the top!! o-ring inside of thr top plate is bad you need to remove the plate /dissasemble and replace the o-ring

Two areas to check when air leaks from around the trigger. Rubber ball under trigger pin will cause air to leak, however when good side of the ball falls on the seat, air will not leak for a while. If air is leaking from plunger pin (just in fromt of the trigger pin), remove the head and pull out the cylinder plate to reveal broken oring (oring part # 876161). Good luck with your repair project.

Oil it. "O" rings or seals might be dry. May need replacing.

Your owner's manual is available at: http://www.hitachipowertools.com/PDF/All/NV45AB2_NV45AB2S_OM_NEW.pdf The adjuster knob to set the depth the nail is driven to is on the same side of the gun you load the nail on, just at the bottom of the head and near where the head of the next nail to fire rests. Pull down on and turn the knob counter-clockwise to leave the nail higher in your work or clockwise to drive them in deeper. When you let go of the knob it will spring back up. With it up turn it until it locks into place, usually another 1/4 turn or less.