AIRGUN MAINTENANCE: Fixing Dragon Slayer 454 leak

[Tofazfou]

Every once in a while we have to stop shooting so much and actually do some much deserved "MAINTENANCE" on our hardware (airguns).....lol.  I had been wanting to shoot my tried and true Dragon Slayer 454 for some time now and i finally got around to ordering some 150 gr. EPP/UG's as recommended by my buddy Chris Butcher for it to test and while i waited on those to come in, i located the case with the Slayer in it and wanted to clean the barrel and to check for any leaks.  Its probably been over a year since i last shot it and no time like the present to check the gun out and prepare it for it's upcoming outing.  Thank God i did cause upon opening the gun case, i found the guns reservoir to be empty.



Before trying to fix the gun, i right then and there decided that i wanted to also install a NEW FILL NIPPLE from Leroy Roduner at BGMF Airguns.com to make filling the gun much more simple.  His part not only takes away the leaky and horrible fill probe that comes with the gun but it also came with a screw on cap to keep out dust and other things that would otherwise clog up the fill port while filling the gun while outdoors.  A very nice feature to say the least and a very well made part.  Getting rid of fill probes is so nice....lol.




Upon filling the gun again then straining off the air inside the fill whip line, i could hear the DS (Dragon Slayer) leaking back through the OEM fill port.  This is a very common problem with the Slayer line of Korean guns.  No problem though as i had done this before.  So now i drain the air tube by shooting the remainder of the air out of the tube.  I then remove the fill housing from the gun and begin to disassemble it to get to the check valve.  Once apart, i used denatured alcohol on the inside to remove any oil/debris and to in general clean the check valve seat.  I then remove the check valve seal and i visibly see wear on the face of that seal so i decided that flipping it over would be the "QUICK FIX".  And if it leaked still, i could try and order the part through Pyramid air or have one made.






I then decide that while the gauge/fill port assembly was apart, i might as well replace the o-rings on the assembly as well as on the opposite end of the air tube as well.  My profession has taught me that when something like RUBBER (o-rings) has been under pressure for years then all of a sudden that vessel looses all pressure, those o-rings should be replaced before putting the item in question (guns air tube) back together.  Rubber changes when its been under extreme pressure and heat and tend to become harder and more brittle.  So change it is.


While the air tube was off, i decided to go ahead and also remove the valve stem and attempt to clean the valve seat with alcohol also.  I also replaced the o-rings on the bolt probe as well, i thought, WHY NOT...lol.  This would be all the maintenance that i performed on the gun and this should put it back in service for at least the next couple of years if not longer.  These fixes/preventative maintenance items are reasonably easy and inexpensive as they only cost you the price of o-rings and a little time.  Nothing last forever and these parts are under enormous stress and are necessary at times when you own PCP's.  As a matter of fact, seals are part of every major type of airgun as seals are the KEY when storing and capturing and expelling high pressure air.  Springers, PCP's, Pump Pneumatics, and CO2 guns..etc..etc..etc..all have them and should be replaced when worn/leak.

Fill port (OEM, BEFORE):



Fill nipple (L.R., AFTER):


STAY TUNED!!
http://tofazfou.blogspot.com/

[lloyd-ss]

Very nice write up and pics!
A question though, is the fill check valve incorporated in the gauge assy or is it now integral with the new fill nipple? Or could it become part of new the fill nipple?
Thanks,
Lloyd

[Tofazfou]

Lloyd,

Thanx for replying to the thread.

The check valve is incorporated into the assembly.  One side of it is the gauge (the long screw with the green heavy spring on it is the gauge side) and the other has the check valve in it.  The new fill nipple is only that.  It's hollow through and through.  But i asked the maker why he did not incorporate a check valve into the fill nipple since the DS are notorious for leaking.  i honestly thought that fill nipple had a check valve in it.

I guess i could add a check valve to it though....lol.  I actually have check valve internals laying around in my garage.

The DS check valve parts are in the 9th, 10th and 11th pic down starting with the pic of the DS.   The 11th pic down contains the SEAL and brass cup that holds the seal.  Those are the parts that leak.

[Rescue35]

Thanks for the information. Once I get moved and the shop set up (again) I'll be digging into my Dragon Slayer.

How does the Dragoon shoot with the .454 barrel? Has any work been done to the internals to increase the power?

[lloyd-ss]

..........................
I guess i could add a check valve to it though....lol.  I actually have check valve internals laying around in my garage.
...........................

I tend to agree.  Seems that the standard fill nipple check, in all of its various forms, is about as simple and reliable as anything in airgunning!   

[Tofazfou]

Rescue,

The Dragon Slayer is basically or IS a Career 300 in 22.  Which is just about the silliest thing an airgun manufacturer can do.  Never try and turn a small bore (with a small bore frame and parts) into a big bore and expect it to compete with the likes of DAQ or HALEY or XP airguns...lol. I like the outside looks of the gun but the internals not so good and space is limited unless you are a machinist and remake everything to big bore specs.  Now in saying that, i'm saying that the smaller the caliber the better the performance.  The gun would probably be at its best even more so in 25-308-9mm.  So, in 454 though, the gun is AWESOME.  For one, 45 cal and 32 cal have a ton of bullets available for it.  Everything from Round Balls up to bison slaying slugs.....lol.  The gun is currently shooting at 250 FPE and it has been heavily modified by me (years ago).  It's MAXED out.  When i first got the gun (DS 50 cal), it shot 183 gr RB's at exactly 610 fps for the 1st shot and 619 fps for the second shot.  The gun was so quiet that i spent about 20 minutes looking for a power adjuster on it....lol.  SERIOUSLY!  My first batch of mods brought the velocity to about 690 FPS with the same ammo (490-495 cal round balls) and it started to bark when shot.  I then went MORE on the internals massaging and i brought the velocity up to 710 fps which is exactly 100 fps faster than stock and finally it breathed fire like a real DRAGON..lol.  I then ordered a 25" Track of the Wolf .454" barrel and sent the gun and barrel to my machinist.  The finished barrel length came out to 24".  Shooting .454"/141 gr Round balls now, the gun shoots 850+ FPS.  I ordered some 150 gr EPP/UG bullets as recommended by Butcher and it pushes those right at 835 FPS for about 230+ FPE.  The gun in stock form made about 150-152 FPE and now it makes 250 FPE.  I've helped a lot of owners reach the potential of the DS.  If you need help or advise please feel free to email me at Tofazfou@gmail.com.  The gun is very simple to mod but remember though, its limited.  260 FPE is about the MOST i've ever heard of anyone modding the gun to and that was a airgun TUNER but, i just don't see how unless they CUSTOM MADE SOME PARTS.  Cause 250 FPE is pretty much the ceiling of that gun but it's easy to get there.

[Tofazfou]

Lloyd,

This is more of a FYI type comment but, i actually would have ordered a plain 4500 psi fill nipple from a paintball store online but, the dragon slayers fill port threaded hole is bigger than the standard size.  A regular male fill nipple that fits most airguns is TOO SMALL in diameter.

One of the things i hate about KOREAN GUNS is that they do NOTHING STANDARD (threads....parts...orings...screws....etc..etc.)....lol.  That's something that i bet you can totally understand were i'm coming from......lol.