Question about Hitachi Air Tools & Compressors

2 Answers

Nv45ab won't advance nails

Removed, cleaned, and lubricated nail feeder assembly. The feed plunger moves freely with no air supply attached. With air applied, feed plunger moves all the way toward piston drive shaft and stays in that position even when gun is continually fired. Feeder piston doesn't move in return direction. What is the movement of air in the gun that moves the feed plunger when the gun is fired and when trigger is released? What causes the change in direction of the feed plunger? Maybe I should be looking for the problem elsewhere instead of the feed plunger assembly.

Posted by on

  • lips0 Jan 24, 2013

    There are two allen set screws located in the exhaust cover. These screws were turned all the way to the bottom on the cover which probably blocked off the air supply to the feed plunger assemby. I backed off the screws so they were almost to the top of the cover. The NV45AB now advances nails correctly. I couldn't find these screws listed on the NV45AB diagram or parts list and there is no reference to adjustments in the repair manual. Newer guns probably don't have these allen set screws anymore.

  • lips0 Jan 31, 2013

    Backing off the allen screw apparently opened up the tube air line to the feeder piston assembly. That along with disassembling, cleaning, and greasing the plunger corrected the problem. It now works great. Thanks.



2 Answers

  • Level 3:

    An expert who has achieved level 3 by getting 1000 points


    An expert that got 10 achievements.


    An expert that got 5 achievements.


    An expert whose answer got voted for 500 times.

  • Hitachi Master
  • 1,388 Answers

The allen screw/s that you mention are there to plug holes where automatic equipment would normally connect (such as automatic nailing machines) . This is only a plug and should not be driven in too far. I have also seen allen screws installed in the head to repair small crack/s.

Posted on Jan 31, 2013

  • Level 2:

    An expert who has achieved level 2 by getting 100 points


    An expert that got 5 achievements.


    An expert whose answer got voted for 20 times.

    New Friend:

    An expert that has 1 follower.

  • Expert
  • 109 Answers

Make sure the feeder spring behind the feeder pawl isnt broken or missing. it pushes the pawl to force the next nail

Posted on May 29, 2014


3 Suggested Answers

  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

a 6ya expert can help you resolve that issue over the phone in a minute or two.
Best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.
the service is completely free and covers almost anything you can think of.(from cars to computers, handyman, and even drones)
click here to download the app (for users in the US for now) and get all the help you need.

Posted on Jan 02, 2017

  • 285 Answers

SOURCE: How do you safely remove jammed nail gun?

Not sure exactly what Bostitch framer model you have, but if it is powered by compressed air, as long as you remove the air hose from the nail gun, there should be no risk of the nail gun firing while you remove the jammed nail. There should be a way to access the driver area from the top of the nail gun, even via a latch or a couple screws. Remove the top part of the driver area and that should give you access to the jammed nail, which you can remove. Use long nose pliers or something similar if the nails are really stuck.

Posted on May 31, 2009

  • 131 Answers

SOURCE: paslode nail gun not firing

Yes you need to oil driver blade piston.
You need to check for spark. With no nail or gas in it. Take of main cylinder(4bolts on top, 2 bolts on nose. And then put in battery. And then push upper switch(behind roller at top) and the fan will come on. And then pull the trigger. You should have spark.

Posted on Jun 23, 2009

Add Your Answer

Uploading: 0%


Complete. Click "Add" to insert your video. Add



Related Questions:

1 Answer

My nv45ab2 will break the wire 3 to 4 nails back and after those feed thru it of course doesn't have a nail to shoot. I replaced the part that advances the nail

Hi Brent:
I'd start by doing a thorough maintenance procedure.
- Disconnect from air (Safety First)
- Dis-mantle, clean and inspect all parts.
- Replace any defective parts.
- Re-assemble and lubricate appropriately.
Connect to air and test.

Mar 21, 2016 | Tools & Hardware - Others

1 Answer

Nails will not move into position after first nail in rack is nailed. Nail feed spring too weak? Nails defective?

Most likely the driver is not returning to top of cylinder, thus driver blade does not allow nails to move into position.
easy to check. With air line removed, insert a thin rod that fits into nose of gun and push up the driver. If the driver moves up, needs orings or seals, if driver is all they up, then problem with rails or feeder spring. Good luck with repair.

Aug 16, 2015 | Air Tools & Compressors

1 Answer

How do I fix dont feeding the nail

The Bostitch rn46 is a very good nailer however suffers from the problem that you are experiencing. Easy to fix. Remove the nails and connect to air pressure (100psi). With side door open and trigger depressed, cycle the gun against old coiled rubber hose or soft wood. As you cycle the gun, check that the feeder is moving back and forward with speed and the driver is moving down then up again. If the feeder seems to move in slow motion back and forth the air passage that feeds air to the feed piston is restricted or oring/spring to feed piston is worn. If the feeder moves very fast then suspect worn driver oring. To check driver oring, remove nails and air supply and leave open side door. Point nose of gun up then down to see if the driver seems loose and is moving up and down the cylinder. When the driver oring is good, the driver will stay at the top of the cylinder. If the driver oring seems ok and the feeder moves very fast then suspect feeder spring weak or missing. I usually find that debris from lower bumper and driver piston oring shavings have entered/clogged the air passage to feed piston. Replace parts as needed. Good luck.

Feb 21, 2015 | Stanley Factory Reconditioned Bostitch...

1 Answer

Roofing coil nailer will not advance nails

The feeder piston should be very hard to retract by hand and should move back and forth as quickly as driver piston moves. With nails removed and side door open, activate gun on rubber surface (old coiled up air hose or water hose ) and make sure driver and feeder move quickly. If not check for debris within feed piston or air passage to feedpiston. The spring straddles the feeder with the slightly bent part of the spring arms contacting the upper surface of the feeder (little grooves cut into feeder). When installed correctly, the tip of the spring arms will be pointing upwards and the back part of the spring between the two loops will be contacting the feeder shaft. Good luck.

Jun 25, 2013 | Porter Cable Air Tools & Compressors

1 Answer

My hitachi nail gun NV 50AA will fire, but won't advance the nails on a regular basis

NV50 nailer is very difficult to repair due to complicated feeder /feeder spring / feeder retainer pin design. You most likely need to replace the orings on the feeder piston. Problem is that you must remove the feed pin/ spring to get the piston out. If you are going to attempt to replace the orings, study how the pin is installed otherwise you will make it worse. Order new springs (2 different springs ) and install them when you are going back together. Good luck

Mar 03, 2013 | Tools & Hardware - Others

1 Answer

Why won't feed plunger advance nails?

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.

Jan 23, 2013 | Hitachi Tools & Hardware - Others

1 Answer

Hitachi NV45AB won't advance nails

This problem could be caused by the head gasket fliped the wrong way not sealing small hole in the body. Also the head valve gasket (small round gasket between headvalve and head) could be place with vent hole mis-aligned. Check these two items and post again.

Jan 22, 2013 | Air Tools & Compressors

1 Answer

Gun is full of nails, but acts like it is empty (the plunger won't advance). You go to tap it with the trigger pulled, and it just does nothing. Seems like firing pin is not getting air or somet

If no air is leaking from the gun, take out the nails, remove trigger by removing 3mm hex head bolt to expose the trigger pin. With air connected and side door open so that you can see the feeder, quickly depress the trigger pin with finger. Gun should fire. If gun does not fire (only makes air sound at trigger) dissconnect airline, remove head and lube headvalve with white grease and reinstall. Test again. If ok replace trigger. If still no joy, replace trigger valve with new factory or generic (part # TVA6). If gun fires but does not activate the feeder claw, remove two 6mm hex bolts from front of gun and split apart upper and lower body and check white oring (part # 149885) Good luck

Oct 16, 2012 | Stanley Bostitch Rn461 Gun Coil Roofing...

2 Answers

I have a porter cable roofing nailer model # RN175 that does not advance the nails everytime what causes this?

Some causes, in order of probability:
Roofing nailers get a lot of tar build up on them, especially around the nose safety and nail feed pawl area. Cleaning off this buildup will usually take care of most problems with roofing nailers.
On the side of the gun away from the side you load the nails on there is a small cylinder with a piston inside that attaches to the feeder pawl. If air isn't getting to the piston or the piston's o-ring or spring is damaged, it won't cycle properly to advance the nails.
If the driver doesn't retract fully, the next nail won't be able to advance properly for the next shot. This can be caused by o-rings in the head that are worn or out of their proper place.

Oct 06, 2012 | Air Tools & Compressors

2 Answers

Bostitch roofing nailer wont return driving pin but moves freely

If the driver moves on it's own then it's o-ring is shot,replace it. Pop the feeder cap and clean all the roof crud that's built up underneath it.Now you can see the feeder spring,check to see if broke or old and replace.The feeder plunger is air assisted so hook the air up and depress it, it should depress hard and pop right back up. If not it needs to be cleaned and new o-rings. If this doesn't work then it's a new feeder plate you need. good luck.

Sep 15, 2009 | Hitachi NV45AB2 Roofing Coil Nailer

Not finding what you are looking for?
Air Tools & Compressors Logo

Related Topics:

229 people viewed this question

Ask a Question

Usually answered in minutes!

Top Hitachi Air Tools & Compressors Experts

John Trevino

Level 3 Expert

1388 Answers

Jim Thurston

Level 3 Expert

670 Answers

Ronny Bennett Sr.
Ronny Bennett Sr.

Level 3 Expert

6927 Answers

Are you a Hitachi Air Tool and Compressor Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides