Tuning Taipan Veteran Leak
- Thread starter kthomas
- Start date
I may be looking at the wrong one, but it looks like 13.5X2, and I received an extra in my spares that came with the rifle.
Upvote 0
I didn't even think to check my spares, thanks!
So I changed out the O-ring from the spare kit (thanks again!), along with hitting the valve face with some emery cloth to get it really polished up. I still can't get fill the airgun up, even with pellets in the barrel. There doesn't appear to be a leak by the grub screw anymore, but when I open the action there's definitely air escaping.
I'm thinking the next step is to take it over to my friend's house who has a bottle, and try and hit it with a quick burst of air in case the poppet needs that to seal. Perhaps the slow pressure of the compressor just isn't enough to get it to seal when it's empty.
Failing that, I'm not sure what to do next. I'm starting to get at my wits end here.
Upvote 0
Scott might chime in, since he actually knows what he's talking about, unlike me. But, if air is coming out the TP, it has to be coming through the valve, doesn't it?
Upvote 0
That's the only thing that makes sense to me.
I'm guessing that delrin "poppet" isn't correctly sealing against the valve face, allowing air to go through to the barrel.
Perhaps a quick blast of air will get it to seat, perhaps I need to touch up the face of that valve some more.
Upvote 0
Generally on TAIPAN's the hammer is in free flight so there is no tension placed upon poppet holding it open ... therefor no need to cock the rifle prior to filling as some guns require.
Now if your having an air leak out the barrel upon filling from empty ... YUP the poppet to seat connection is compromised being either dirty, small hairline dent on the softer poppet or the poppet face itself just heavily worn / grooved from impacting seat. You can ( In a lathe ) by holding onto stem, spin poppet head and make a minimal clean up pass on the seat side removing the wear groove present ... make a new poppet head or just replace it.
As to the SEAT ... if you take it out you will notice that on the poppet side the face around the throat has a slight machined backward angle that creates a rim of contact on the inner most diameter. Take an eye loupe or good magnifying glass and look at the inner edge making sure it too has NO DAMAGE, small dents etc ... If it does you can lightly dress the face with 600 wet/dry on a piece of glass or granite etc to just kiss this surface and remove a minor surface imperfection where the poppet is in contact if present.
And as you noted ... a FASTER initial filling in the first 500 psi or so can get plenum space to pressurize faster and in many cases the poppet will seal right up and give no further trouble.
Scott S
Now if your having an air leak out the barrel upon filling from empty ... YUP the poppet to seat connection is compromised being either dirty, small hairline dent on the softer poppet or the poppet face itself just heavily worn / grooved from impacting seat. You can ( In a lathe ) by holding onto stem, spin poppet head and make a minimal clean up pass on the seat side removing the wear groove present ... make a new poppet head or just replace it.
As to the SEAT ... if you take it out you will notice that on the poppet side the face around the throat has a slight machined backward angle that creates a rim of contact on the inner most diameter. Take an eye loupe or good magnifying glass and look at the inner edge making sure it too has NO DAMAGE, small dents etc ... If it does you can lightly dress the face with 600 wet/dry on a piece of glass or granite etc to just kiss this surface and remove a minor surface imperfection where the poppet is in contact if present.
And as you noted ... a FASTER initial filling in the first 500 psi or so can get plenum space to pressurize faster and in many cases the poppet will seal right up and give no further trouble.
Scott S
Upvote 0
The factory valve body brass is extremely soft, and the sealing surface is very easily compromised. I doubt that the nylon valve poppet itself is the problem, so if you need a replacement body - let me know.
Upvote 0
I've assembled and disassembled multiple times now, touched up the face of the valve with some very fine grit emery cloth. However, I still seem to have a leak coming out of the port with the grub screw. That o-ring has been changed out, and I've also tried applying some silicone oil to it.
Is there any tips/secrets to fixing the leak from the grub screw port, beyond what I've already done?
Is there any tips/secrets to fixing the leak from the grub screw port, beyond what I've already done?
Upvote 0
As you are aware ... The Valves BRASS BODY simply sits there, grub screw only Clocks the transfer port to align straight up, o-ring that is up against valve body seals the valves face to the wedge face of the tubes end cap.
ONLY WAY air will leave this connection is if the O-ring is not making a seal between body face and tapered end of cap .... period.
Your missing something IMO ?
ONLY WAY air will leave this connection is if the O-ring is not making a seal between body face and tapered end of cap .... period.
Your missing something IMO ?
Upvote 0
I'm not sure what exactly you are referencing when you say throat, but I did this:
https://www.youtube.com/watch?v=7r1LG_n9XnU
Upvote 0
Sounds like you BROKE THREW the side of the valve body making a hole. You may not see it, but if there was an area that was thin, under pressure it may have very well ruptured/split and where the air is getting past the poppet and o-ring no matter how well there sealing.
OR ... in thinning material behind the sealing surface it now is too thin having the "Bridge" of material between transfer hole and throat, poppet side face unable to support the load of the poppet against it or the o-ring crushed against it and the edge in that area simply bends inward & no longer flat and leaks !!
How about a PICTURE or three of what you did .. it will be telling.
Scott S
OR ... in thinning material behind the sealing surface it now is too thin having the "Bridge" of material between transfer hole and throat, poppet side face unable to support the load of the poppet against it or the o-ring crushed against it and the edge in that area simply bends inward & no longer flat and leaks !!
How about a PICTURE or three of what you did .. it will be telling.
Scott S
Upvote 0
Scott,
I'll get some pictures posted up tomorrow. I wouldn't be surprised at all if I somehow botched it up.
Thanks everyone for the replies so far! Your comments are all appreciated.
I'll get some pictures posted up tomorrow. I wouldn't be surprised at all if I somehow botched it up.
Thanks everyone for the replies so far! Your comments are all appreciated.
Upvote 0
It looks like you might have a little nick at the poppet sealing surface. It's also flared out too much at the exit port.
I can send you a factory spare if you can't fix it.
I can send you a factory spare if you can't fix it.
Upvote 0
Oops saw you already did! Have you tried divers grease?
I can't believe I didn't tell you to plug the fill probe in to the gun and while holding it in the fill port with one hand start your compressor and with 2 pellets loaded in the breech pointed in a safe direction bang the hell out of it at that valve seat area with a rubber mallet while the compressor is chugging along. You are using the banging vibration to jiggle that valve poppet to force it to seat with zero pressure while the compressor tries to slowly fill it.
How on the hell did I NOT mention the HAMMER TIME TRICK EARLIER? I usually do (OH probably didn't PM you to beat it to death) Since its too graphic for readers.
I can't believe I didn't tell you to plug the fill probe in to the gun and while holding it in the fill port with one hand start your compressor and with 2 pellets loaded in the breech pointed in a safe direction bang the hell out of it at that valve seat area with a rubber mallet while the compressor is chugging along. You are using the banging vibration to jiggle that valve poppet to force it to seat with zero pressure while the compressor tries to slowly fill it.
How on the hell did I NOT mention the HAMMER TIME TRICK EARLIER? I usually do (OH probably didn't PM you to beat it to death) Since its too graphic for readers.
Upvote 0