20 Most Recent Dewalt Heavy - Duty 31° Clipped Head Framing Nailer - D51822 Questions & Answers

open the hood and closely examine each of the wires that attach to the injectors those are the electrical contacts on the top each cylinder has one. thus multi- point fuel injection, ok one of those wires is broken. find it and repair it heat shrink tube works, just don't use open flame, a heat gun will work.

Joe, hey not sure what the d51822 brand name is I work on bostitch as a service tech. so well the obvious question with the details you've given 45 degree angle? so are they bent over to get that angle? not sure how they can come out straight and get bent. ok the nose ( where the nail comes out) is it completely flat on the board? if so I would be nearly impossible to create a 45 angle. not doubting you. I work on F28WW bostitch thinking they are similar so, check the bolts on the top (loose or damaged) or the nose its self see if it is bent. it would be only slight because otherwise the driver ( what pushes the nail in) would get jammed and not fire at all .try that first thinking the nose is bent and if its bent its junk. because cracks are next and that's when really bad things happen fast.

Dewalt guns use between 70 and 120 psi. I use 100 psi on all framing guns when testing, however the nailer will last longer if you use lower pressure (only whats needed to drive nail into work, depending on type of wood) . When too much pressure is used, extra force is absorbed by the lower bumper and nose area of gun. The address below is dewalt service and has all the info about your nailer. Just enter the model number and look for pdf file. Check your model number for safety recall. Good luck www.servicenet.dewalt.com

Either the plunger has not completely returned to the "pre-firing" position, or there is a defect in one of the o-ring seals. Make sure that the gun is sufficiently lubricated and if so, then next check the condition of the o-rings. An improper seal will cause this. It is also possible that the trigger assembly has a small crack/leak.

Dan

Most likely the two orings that make contact with the cylinder spacer (white plastic piece around the cyl.) and the cylinder are leaking between the chambers and out the nose. Pull out the cylinder and remove all the lower parts so that you can slide the cylinder out of the spacer. Replace the two large orings (dewalt uses vinyl orings under the cylinder spacer and they fail). Reinstall using white grease and retest. Good luck.

Dewalt nailers have some vinyl orings that fail. Usually found within the trigger valve, headvalve, and between the cylinder and cylinder spacer (white plastic piece). A dewalt nailer with failing orings may not leak air however. The vinyl orings tend to start to crumble and the tacky-crumbling pieces tend to create a seal. Easy way to check condition of the vinyl seals in a Dewalt is to remove the trigger valve and look at the orings on the firing pin/stem (2mmx1.5mm orings). If these two orings are soft and sticky, then orings inside of gun most likely the same. Check band on the outside of the cylinder (part # 390159-00) is what causes piston to return to top. But also check to too tight or too loose piston oring, bent shaft of driver and worn/ broken lower bumper. If all is well with internal parts and piston does not return to top, too much air is leaking past nose of gun. Oring kit sold by dewalt will contain most of the orings needed. The kit may not have orings for the trigger. You will at need two orings (2mm x 1.5mm) for the trigger valve stem or just replace the valve. Use white grease or silicone paste lube on all the orings. Good luck.

Duplicate

Dewalt framing nailers use some vinyl orings (gold or clear in color) that fail too soon in both the trigger and the cylinder spacer. Air out the nose of gun indicates air is leaking past the cylinder spacer seals (If piston is pushed down with air leak then headvalve seal is leaking (remove nails for this test)). If piston is not pushed down with leak, remove head and pull out the cylinder with cylinder spacer (white plastic). Place the cylinder on workbench with bottom up. Push down on locking ring and remove retainer to release all the other parts. Take picture or take note of parts together and as you pull them off to aid in re-assembly. You will need to replace the two orings between the white cylinder spacer and the cylinder. Order oring kit from dewalt or just purchase one ( # 141 universal oring ) and one metric oring 74.4mm x 3.1mm from hydraulic parts store. If the piston was pushed down with air leak, replace headvalve orings in the head. Good luck with your repair

I had a similar problem with one of my nail guns. What I found was a small rubber o-ring in the trigger mechanism had split. Once I replaced this the problem was corrected and the unit functioned fine.

You could replace the whole trigger assembly for about $35. But if you remove the assemble and replace the split-ring this would only cost a couple of bucks at most.

Trigger assembly shown below. ereplacementparts.com is one possible source for the trigger assembly others can be found on the Internet.

Dewalt has a new trigger valve to replace the original (part number 5140095-73). Not sure if the new valve is replacement to address an issue or natural progression. I would also replace the orings that make contact with the reference #55 on parts list called the bulkhead. There are four orings contacting the bulkhead that wear and may contribute to multi-fire. Parts are at dewalt service center or at www.toolpartsdirect.com Good luck

Sounds like the piston seal is bad you can see parts breakdown and order parts from

http://www.ereplacementparts.com/search_result.php?osCsid=vo9ttiinh4kt2ecdqi1a619kl5

You need to check the label and see if it is a type1, 2,3, or 4
I suggest you order the O-ring kit