20 Most Recent Dewalt D51256K 16 gauge finish nailer kit Questions & Answers

O rings

Dewalt D51256K... | Answered on Feb 04, 2019

A scroll spring a part in the drawing parts pos 25 and 26 must be smooth and not kinked the slide must free adduce the nails smoot in part pos5 clean it or repair it.

Control after by Open pos 20 by part pos 22 the nails can come out inthe middle of pos 21 all can jump out the front if nails are placed maybe its hanging on the top but then a part come out ,the mounting of pos21 on pos 5 can have a problem but the last option is the quill come high enough back ? enough pressure ?


Dewalt D51256K... | Answered on Dec 28, 2016

There are much parts not more available anymore and to service this nailer on parts the cilinder on the top rings seals and o-rings on the left on the drawing are the parts inmost cases to service but a safety lock can have problems by os 23 contact trip that it will not come enough to p[ush part 32 but most case the valve in the top head will not working smooth dirty/dry or broken o-ring top seal

Dewalt D51256K... | Answered on Dec 28, 2016

This problem is due to failed orings in the gun and the trigger valve. If you have access to orings, replace all the vinyl orings that feel sticky or like putty (at least 3 in the trigger valve). Finally, make sure that the driver blade moves freely within the cylinder and that there are no jammed nails within the path of the driver.

Dewalt D51256K... | Answered on May 05, 2016

It may already have a nail jammed in it. You may have to take off the front face that holds the firing pin. There should be one or two screws in front just above where the nails come out. If you remove these there will be a plate that comes off and then you can remove a jammed nail. Look first to see if there is a jam before doing this. Also maybe you have the wrong guage nails or maybe you don't have proper air pressure. Hope this helps.

Dewalt D51256K... | Answered on Apr 19, 2015

No - this nailer must be oiled (5-10 drops directly in air fitting before each use)

Dewalt D51256K... | Answered on Feb 07, 2015

Take a look on amazon for it: Amazon com dewalt trigger valve I hope this was helpful. Have a nice day

Dewalt D51256K... | Answered on Dec 21, 2014

1) Check to see if the drive belt is intact
2) Check and make sure the driver blade is not bent
3) Make sure return device is properly clipped down so the driver can fully retract
If you don't have success, please let me know more details of what the tool is doing and I will try to talk you through it.

Dewalt D51256K... | Answered on Jul 21, 2014

Replace the trigger valve part # 647956-00 to solve this problem. If you have access to very small orings (2mm x 1.5mm), try replacing the two orings on the trigger valve stem. Dewalt uses vinyl orings on the trigger stem and they fail causing malfunction. Easy fix however and not expensive . Good luck

Dewalt D51256K... | Answered on Apr 21, 2014

Enter your model number at the web address below for manual. You can also purchase replacement parts. Good luck with your nailer.


Dewalt D51256K... | Answered on Sep 08, 2011

Check your manual, most guns take a drop of air gun oil in the end of the gun where you hook up to the air hose. One or two drops every time you use it only if you use it consistently all day. Otherwise one or two drops a week.

Dewalt D51256K... | Answered on May 06, 2011

I am not familiar with that particular nailer but on most there is an adjustment screw or "barrel" nut that allows you to adjust the depth of the driver. If this has rattled loose as is often the case, the nail heads will be left sticking up. If that doesn't solve the problem, there is the chance that something internal has come lose and is inside the ram - preventing it from driving down all the way. If this is the case then it can destroy the inside of the tool and will need to be torn apart to be repaired. IF you are to repair it yourself I would suggest going to Dewalt's web site and see if you can get an exploded view of how it comes apart. As you take it apart take pictures of your progress so you can look at them when reassembling it. I did this recently with a Bosch jigsaw and was very glad I did once I found out how many parts were inside! Good luck and hope I was helpful.

Dewalt D51256K... | Answered on Feb 24, 2011

That sounds right. If it is driven off air, try putting some oil drops in the air inlet and see if it works loose.It may be stuck because it will not continue to shoot if stuck open either

Dewalt D51256K... | Answered on Jan 19, 2011

Not finding what you are looking for?
Dewalt D51256K 16 gauge finish nailer kit Logo

30 questions posted

Ask a Question

Usually answered in minutes!

Top Dewalt Tools & Hardware - Others Experts

John Trevino

Level 3 Expert

1420 Answers


Level 3 Expert

1997 Answers

john h

Level 3 Expert

23424 Answers

Are you a Dewalt Tool and Hardware - Other Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides

View Most Popular

Dewalt Tools & Hardware - Others

  • Dewalt Tools & Hardware - Others

Most Popular Question

d51257 nailer will not

  • Tools & Hardware - Others