FX Need ORing Help With FX Impact MKII AMP Regulator

I developed a slight seeping leak from the weep hole right behind the trigger safety, so I am rebuilding the regulator on an FX Impact MKII w/Power Plenum. I've replaced all orings both internal and external on the entire regulator assembly and they were all pretty brittle. I am now trying to replace the last oring to complete the regulator reseal... the C39 #19790 oring that is inside the regulator tunnel tooled into the main receiver assembly. It seems brittle as well, as I'm having difficulty sticking it with a fine point pick to unseat it from its channel. Not wanting to scratch anything, I'm stepping back to evaluate, and was wondering if there are any tricks to get a brittle oring out of that channel? I was thinking about applying some heat from a heat gun to maybe warm and soften the old oring and try again. Any reason I can't do this, or cautions? Of course, by now I'm committed, since I'm sure I've nicked the old oring in the attempts to routinely remove it. Last one I changed was easily pricked and flexed right out of the channel. This one is scaring me. A nick in the housing or channel in there is not good. Any help or advice would be appreciated.
 
That particular O-ring is difficult and frustrating to get at. When I last worked on my MKII regulator O-rings it was with a pair of Nylon pick tools and the one that worked best was the angled flat tipped unit. It took some time and patience but finally pushing the flat tip behind the O-ring allowed me to pry it out of the groove and then out of the hole. Good luck to you.
 
I tried brass o-ring picks with no success. The picks were too soft and not sufficiently strong to maintain shape. After much head-scratching, I used a carpet needle and a small brass hammer to "spear" the o-ring. The next step was to grasp the needle with a pair of pliers, pull the o-ring away from the channel, and slip an o-ring pick between the o-ring and the channel. At that point, the o-ring was easy to remove.

JackHughs
 
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All good ideas. I think the real problem is the hardening of the oring and it has flattened out to be almost flush with the wall of the tunnel it's set into. No flexibility at all, very little to get a needlepoint into, and yet loose and will slip and spin in the groove it's set it. I think I'm going to have to get a break in the oring to get it out. I've weakened it in a few placed but still no separation. I'll keep at it.

I hear ya, Trucker. I've moved my competition platform to Skout (EVOs), and I cannot believe the well-thought-out serviceability engineered into the Skout platforms. I will always love and admire the Impacts, and they are shooters, for sure, but a new manufacturer and gun now checks more of the boxes I need checked. And it shoots every bit as well. It was time.
 
Well, I think I got through it unscathed. Or more importantly... unscratched. Although I don't know how. I ended up having to pound an angled dental pick flat, then shape it to be like a mini angled front-edged knife that was narrow enough to fit into the oring groove. From there I heated it to red hot to get a cut in the oring. Once I finally got the separation in the oring, normal picks helped me get the broken brittle oring out in 5 pieces. After having been depressurized for a while during this evolution, upon pressurizing after successful regulator rebuid/reseal, I had a couple other misc orings leak slightly, so I replaced a few other orings, and it now seems to be holding air fine, at least initially. Gonna give it a few days for leak testing and go from there. Thanks for all the suggestions!
 
That oring should have been in a groove on the outer perifery of the reg. I have no idea why FX chose to put it in a hole. That's really the only hard part so we live with it.
I'm not about to get rid of Fx rifles over it.
I agree totally. I have not been able to identify any reason that oring is not on the reg body (maybe the reg body wall isn't thick enough and it's just not obvious to the user). Just doesn't make sense to me, but like you, I've lived with it for 6-7 years now. In all fairness, though, this is the first time I have had this much trouble, and if I had done a preventative reseal earlier instead of a reactive reseal after leaks started, I probably wouldn't have had that much trouble. These orings got older than they should have and hardened. That's on me. I resealed another MKII reg 5 or 6 weeks ago, and I had more problems getting the new two small orings on the reg adjuster pin than I had getting the oring out from inside the reg tube. That oring was still very pliable and took a stick and pull to come right out of the groove. I was actually very surprised.

I also didn't get rid of my FX rifles over this oring ordeal. Until about 4 months ago, I had never owned or shot anything but FX Impacts. I even went to the Pyramyd Air Cup last September with the intention of upgrading to the M4 for the better trigger, even though it was disturbing that the only improvement I was really getting over my M3 was the better trigger. I was just ready to retire and upgrade my MKIIs. Shooting on the same benches as and beside some SKOUT Factory Team and High Pressure Pneumatics Team shooters, I got to talk to them a bit. I also got to see the Skouts being used. I decided to wait on upgrading to the next Impact.

Aside from the serviceability (I had always accepted the oring intensive build and very involved teardown of the Impacts), the three main things I disliked about the Impacts were:

1) Barrel liners
2) Sub-standard trigger for the level of the gun
3) Foreign manufacturer (this was compounded by the FXUSA fiasco)

The Skout platforms now have solid barrels (full bull and hybrid bull), the electronic trigger is far superior to my M3, and the Corporate HQ/Factory is a 6 hour drive from me, not to mention local on my cell phone vs international if I want to talk to someone at the factory. An added benefit is the level of customer service from Skout is impeccable. I heard this from every single person I talked to about Skout during my research before switching from FX to Skout. Then, I experienced it. I emailed Skout to ask a few questions about the theory of operation, and the tuning process and the details of its differences from the Impacts. I expected the typical few days before I would hear anything back via email, but within 1 hour, I received a call from Bill Gardner, the owner of Skout Airguns. He had seen my email and wanted to talk live so he could be sure I got all my questions answered to my satisfaction and be certain I had a clear understanding of the tuning process and operations of the Skout guns. Six years as a loyal FX customer and solely dedicated FX Impact user, and I never got so much as an email reply from Fredrik Axelsson. Should I have expected a call from the President of FX? Of course not. I didn't expect a call from the President of Skout either, but I got one.

So... solid barrels, a superior trigger (my opinion... I acknowledge that some people will NEVER feel an electronic trigger is superior to any mechanical trigger), Americal made, superior customer service, and better serviceability. Please don't think I was suggesting you get rid of your FX rifles because of a difficult to change oring (where an accidental scratch changing a $0.15 oring renders a part costing hundreds of dollars useless). I'm just saying that another airgun company now offers a rifle that gives me the rest of the things I want in my $2300-$2500 airgun and I don't have to give up accuracy to get them. Since I was looking to upgrade anyway, it was time for me to make the switch. If you get everything you want from your FX rifles, it's clearly not your time to switch, and I suggest you don't.
 
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Rather than rebuild the Amp in my Bobcat I opted to throw money at the problem and bought a Huma Air replacement. Much better, easy to adjust, easy to maintain.
I upgraded both regs on my M3 to HUMA regs. The HUMA Reg 1 for the tank seems more responsive and more consistent. The second HUMA Reg is not much different than the newer brass piston version of the FX Amp Reg 2 for the plenum, except the piston seal/seat (Delrin?) on the newer FX Amp is affixed to the end of the brass piston. If for some reason the seal/seat get damaged or dimpled, and needs replaced, the whole piston has to be replaced. On the HUMA Reg, you have a separate tiny seal/disc that you can flip over to a fresh surface and continue with a new seal. After the first flip to reseal, you can replace just the disc if a new part is needed, and the reg comes with a couple spares. Again, well-thought-out serviceability from HUMA.