Author Topic: MY Modified Bulldog is Leaking Air (Read 3146 times))

Airgunhunter73 · « **on:** May 26, 2019, 07:44:38 PM »

Hey fellows my modified bulldog with the gen 1 JSAR balanced valve is leaking air out the barrel, I tried cocking it but no luck there had it out to the range about a week ago an it was filling and shooting fine went to shoot it today and it was empty of air so when I tried to fill it, it just blew air out the barrel so I cocked it an it continued to leak an not take air never had a problem like this with it before all thoughts on this would be appreciate as I haven't had time to tear into it and won't till Tuesday. Thanks in advance Terry

RichH · « **Reply #1 on:** May 26, 2019, 08:35:59 PM »

If it's coming out the barrel that means it's coming thru the vavle, so my guess would be the poppet not sealing.

Airgunhunter73 · « **Reply #2 on:** May 26, 2019, 08:49:29 PM »

Hey Rich that was my thought also but figured I'd some of the more knowledge folks before I tear into, must be my week I'm having the same problem with my Corsair 308

Kinetic45^ · « **Reply #3 on:** May 26, 2019, 10:03:37 PM »

Flow air into the fill, even 100 PSI will do
Then while the air is flowing cock and fire it.
It probably will seal

Sometimes you have to block the barrel too by loading a slug or by putting a cork in the muzzle (on the Bulldog or Pitbull you might have to pull the shroud to do this - depends on how you have it configured) flowing in air and shooting it so pressure builds up and dropped off through the valve. Please aim safely if you loaded a slug and make sure it shot out if that's the method you used (I was told this by another Bulldog owner and it worked but I had to take a cleaning rod and push the slug back to the rear, fill the rifle fully and shoot it for real into a backstop... But the valve did seal the first time, just not enough pressure to fully shoot the bullet)

Airgunhunter73 · « **Reply #4 on:** May 26, 2019, 10:48:13 PM »

Carl thanks for the information I'll try that tomorrow I really appreciate the help was hoping not to have to take it apart again so many dank screws. lol

PCPhack · « **Reply #5 on:** May 26, 2019, 10:58:35 PM »

If the already posted ideas don't work, then the poppet stem is probably frozen in the shaft in the open position. Some of the JSAR ones have so close tolerances, they can get stuck. I know, it happened twice to me. Then finally, if you had it stored with over pressure, the poppet could have cracked. This can happen if you stored it around 3000 psi, and then it got hot, driving the pressure up.

Airgunhunter73 · « **Reply #6 on:** May 27, 2019, 12:31:58 AM »

Thanks David I general store it at a lower pressure after I've been shooting I'll try Carl's method if that doesn't fix it I'll take it apart an see what's up and report back on my findings appreciate all the help.

Airgunhunter73 · « **Reply #7 on:** May 27, 2019, 12:36:13 PM »

Well guys I took Carl's advice and cocked an chambered a round had it pointed into my boolit trap and it took air filled up to 3000psi and fired it, and it went brrrrrp but held air so I filled back to 3000psi took it outside to try the 125gr NOE BBT HP first shot brrrrp second shot brrrp first time it's ever done that seems like I read something about that happening to someone else?

wimpanzee · « **Reply #8 on:** May 27, 2019, 12:44:12 PM »

Sounds like hammer bounce from a too heavy hammer and a too easy to open valve.

Airgunhunter73 · « **Reply #9 on:** May 27, 2019, 01:06:59 PM »

Thanks Wimpanzee it's never done that before but I'll back it off and see if that cures the problem.

Airgunhunter73 · « **Reply #10 on:** May 27, 2019, 01:45:03 PM »

Well I backed the hammer spring off 4 turns and it's still doing the same thing brrrp, I don't know what else to do.

wimpanzee · « **Reply #11 on:** May 27, 2019, 02:42:10 PM »

Quote from: Airgunhunter73 on May 27, 2019, 01:45:03 PM

Well I backed the hammer spring off 4 turns and it's still doing the same thing brrrp, I don't know what else to do.

I didn't mean the spring tension, but the weight of the hammer itself. My marauder used to do the same thing, with my cobra valve and stock hammer. using a lighter weight hammer (hill, 30gram) prevented the hammer bounce from having enough force to re-open the valve.

Not sure what the exact recipe for the bulldog is, but if it has a SS valve, it might need a lighter hammer.

jkingsouthafrica · « **Reply #12 on:** May 28, 2019, 02:15:25 AM »

Sumatra Air Rifle tend to have the same issue normally its the poppet collapsing into the face of the valve and been pushed into the valve body this causes the air to leak out the barrel and when you try to fire it the gun will almost have no power because the poppet isn't moving freely and cant open properly

MJP · « **Reply #13 on:** May 28, 2019, 02:24:07 AM »

Something wrong with the balancer piston or o-ring. Time to take it apart.
Could be damaged O ring and it has gotten piece missing that has blocked the balancer passage.

Or debris in the air that has damaged the valve seat. If it's the air it could affect both of your guns.

Marko

Ironman482 · « **Reply #14 on:** May 28, 2019, 02:15:41 PM »

My bulldog with the jsa balanced valve started making the burbing noise and dumping air after about 60 rounds, I never did figger out what the problem was ,installef the stock valve now no problems, sent thw valve to matt haven't heard back from him yet.

Airgunhunter73 · « **Reply #15 on:** May 28, 2019, 09:51:23 PM »

Hey Fellows
Well I've had it apart 4 times today clean the valve up and everything else the stem was sticking in the valve so I clean the stem with some emery cloth not to much put it together it worked for 5 shots and then wouldn't shoot at all so I called Travis he told me to chuck it up in my drill and use emery cloth to polish it down some so it would just fall out of the valve I did and it did fall out freely put back together 8 shots it quite shooting again, so 4th times charm I took it back apart and put the factory valve back in it I'll try that tomorrow an see what happens fingers X. Just want y'all to know I appreciate everyone trying to help me out with this problem.

Thanks Terry

MJP · « **Reply #16 on:** May 29, 2019, 03:42:05 AM »

If the valve is sticking then there could be silicone in the stem bore. Silicone and aluminum against steel stem is a big no no. It wont lube that combo, it will seize. Some ceramic lube like Krytox will work on the stem.

Marko

Airgunhunter73 · « **Reply #17 on:** May 29, 2019, 09:59:50 AM »

Thanks Marko I had used silicon on the stem but after I spun it in the drill I used alcohol on a Qtip to clean the valve and stem before putting it back together I didn't put anything on the stem so maybe being dry wasn't good either I do have some Krytox, I'm going to see what kinda numbers I get with the factory valve and see if I in counter any problems and then try the JSAR valve again an put some Krytox on the stem. Thanks for the advice on the Krytox wasn't sure about using it on the valve stem.

Airgunhunter73 · « **Reply #18 on:** May 29, 2019, 12:57:49 PM »

Well guys I put the factory valve components back in and the results are it's shooting great so far I'll continue to work on the JSAR valve and try it at a later date or maybe just sell it. I shot 3 5 shot strings this morning over the chrony an here's the results. So my conculsion at this time is a 2900psi fill is the best with the factory valve setup and now to the range for accuracy testing when I have a dry day. Ironman by what Travis told me yesterday the bulldog valve has a lot of anodising so you have to spin the stem in your drill using emery cloth for the stem to work I'm guessing I didn't turn it enough maybe later.

NOE 148gr cast HP NOE 124gr cast BBT HP Aeromag 128gr HP
1-791 3100psi 1-926 2900psi 1-907 2900psi
2-881 2900 2-912 2700 2-895 2700
3-843 2800 3-892 2500 3-863 2500
4-833 2500 4-855 2250 4-829 2250
5-813 2300 ending psi 5-823 2100 ending psi 5-819 2050 ending psi

Airgunhunter73 · « **Reply #19 on:** June 02, 2019, 02:48:17 PM »

Here's a before and after pic of the NOE 358 152gr HP mine's dropping at 148grs shooting into my muddy backyard at 25yds.

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MY Modified Bulldog is Leaking Air

Author Topic: MY Modified Bulldog is Leaking Air (Read 3146 times))