Rebuilding FX Royale 400

[bchannell]

Air rushing down the barrel. I assume that means the main firing valve is leaking through. I replaced all o rings and still the same. Il thinking the seat o ring is the likely culprit. The seat itself is steel on steel. How does that seal?
Also, if I try to use the recommended o ring on the seat itself it is way too large and shears off up insertion, what's up with that?
Watched a video on YT and he pushed the seat in easily, any clues?

 

[joelayfield]

i have to ask a stupid question , are you able to get a charge in your gun ? is it holding a 1000 pounds plus and leaking down ?

 

[Gr8Recreation]

Did you try to remove the barrel shroud and twist it? Think you can gouge something that will make it leak. Can’t recall. Saw that happen and bring fixed where they had to refinish it.

 

[COSTAS4597]

Replace the valve seat with a new one. It comes with the o ring. I would replace the valve as well. There is a slight deformation somewhere that you can't see and you have the leak. The seal is not steel on steel. It's steel on Delrin.

 

[bchannell]

I cannot charge it with air as it leaks almost as fast as air goes in. I do think it has to do with the stem and seat. It looks to me like the delrin is not hitting the steel seat and has worn some.
I placed a gigantic order for nearly every part you could possibly need, so I "SHOULD" be able to fix it when I receive the parts from FX. By the way, they are great to deal with and very helpful.

 

[Roachcreek]

At times the surface area in the receiver that the valve seats against can get damaged from dry firing or shooting the rifle down to bleed downn the pressure in the tank. When this happens a new oring replacement will not cure the problem.

This happened to me a decade ago and I was advised the fix was to insert a large drill bit into the receiver after everything had been removed so that the bit rested upon the damaged surface described here. Then you slowly and gently turn the drill bit with your fingers to cut away the damaged surface leaving a surface that the valve can once again seal against.

I did the procedure, but it scared the heck out of me.

However, it worked and the valve sealed. I don’t recall what sized bit I used, perhaps other readers can chime in as I don’t recall all the details.

Good luck,

Roachcreek