Hitachi na90ad leaking from rear and from front where in nail comes out from still fires ok

insure that there is no debris ie., free from filings from the nails used or or ceck the feeder ports where the nail enters before it lives the port ( check for damage orifice or abstractions to it

90mm nails are too long to allow the piston to work

gas pattern valve ?

Hi Gene,

OK, so there's a factory recall on this one as you understand it. Have you been in contact with Hitachi, or one of their service centres to check this is correct?


If this is NOT the case, it could possibly be that the timber you're using could be too hard??? just for you're own piece of mind, have you tried to fire the same nail into some soft pinewood to see if the result is the same? You've got everything else under control - pressure, leaks etc. so, the timber density may be the issue?

Does the motor start when you depress the nose against the work.
Look at the green light near the battery compartment it should flash one when you pull the trigger.
Is the gas in date?
Try warming the gas first by putting it in your pocket for 10 min before use.
You may also have an air leak, when was it serviced last?
Remove the head assy and reconnect to see if it is sparking when you depress the switches. Do not have the gas in whilst doing this.

This gun should be bump-fired only. Do not place the gun on the work and press trigger. Make sure that the safety spring is in place and has good tension. The spring helps to push the foot off the trigger so that it fires once. You could also adjust the screw that pushes on the firing valve. Turn in or out several turns till head of nail is correct when bump firing then lock the nut. The safety foot fits rather loose on the gun and should still work ok but can get so loose that it falls off the nose. Good luck

Remove the nails and air supply. With side door open notice position of driver. Driver should be at top position with tip not visible. If driver is down and it moves within cylinder when you tilt nose up then down again, time to replace orings. If driver is down, it should extend past the nose about 1/4 inch (if driver is broken at the tip the end will look rough and nail will not drive in all the way). If driver extends past the nose more than 1/4 inch then lower bumper may be breaking up /cracked. Easy test for proper function. With nails removed and side door open, connect air to gun and dry fire gun against hard rubber or old coiled air-hose (with air connected and trigger depressed, no air should leak from trigger area, if air leaks when trigger is depressed, look for fault at trigger pin). Feeder should move back then forward in quick motion almost matching speed of driver and driver should not creep down between shots. No air should leak from nose of the gun (push nose against hard rubber and depress trigger and hold in this position, driver should stay down with very little or no air leaking out of nose, when you release trigger, driver will return). If air leaks out of nose while holding in this position, replace lower bumper. If a quantity of air leaks from valve in front of trigger, cylinder orings may need replacing or outer part of cylinder has fine scratches (remove scratches with 400 grit paper). Parts are available at www.toolpartsdirect.com. Good lucki

remove all the nails and remove the air hose. BUMP the tool on something and does the driver come down on its own if so it needs new o rings. also take a look at the feed pawl for a broken spring that would prevent it from feeding nails and lastly look at the coil of nails to make sure they pull freely. Let me know if you need more assistance.

Hi,
It is common to see sparks. It is metal striking metal. Although, if it sparks alot. It could be a chipped driver blade and the nail would not drive all the way. Does your sink `em?

Does the fan run and the light blink ont he nailer? I have one that I just bought. I put in the wrong type of nails and got one stuck. I had to take the front apart to clear it and now the damm thing wont fire. The green light blinks and the gas cartridge is basically full, even the fan does run after I release the push lever, but no fire???

I wonder if yours is the same as mine did fire for a couple nails first just fine then got jammed...

I will try to charge the battery more.... MAybe like yours it needs a strong charge for the spark...
Russ