Tuning Fx Wildcat Gen 1 leaking issue

With all the mk1’s and MK2’s that were listed in the classifieds last summer with the coming of the MK3, I was highly assuming the guns on this tread were previously owned. I wasn’t directing the over filling of the gun directly at anyone on this tread, as I don’t know if you all are the original owners.

No problem for me I just wanted to sorta eliminate that thought from the potential problem. Of course when I filled the air tube last night it was a hot fill from empty and there was some cooling off and lowering of pressure. I just topped it off and we will see if it holds the pressure. If it holds I think it might be that I use silicone grease to do the first few seals. As I mentioned before I just bought a bottle of Super Lube silicone oil and it is possible that the thinner oil does a better job of sealing the o-rings. Holding my breath. Thanks Bill
 
Well I just looked at the air cylinder gauge and it has leaked down about 50 bar from yesterday. Related to the issue I did also replace the cylinder end o-rings and the check valve o-ring and also the dowty seal. I saw someone on youtube that used a pressure gauge with fitting and bleed valve to attach to the air cylinder end to check for leaks. I have an analog gauge and if I new the thread on the end of the cylinder maybe I could make-up this tool to confirm the leak is in the cylinder. Otherwise maybe I need to look into replacing the valve pin assembly and valve seat. Hate to have to send it off for repair but that might be in the cards. Bill
 
Bill, top off the gun, and fire it for about 10 to 15 dry shots. Do it slow and deliberate, like as if you were target shooting. Then re top off and see if it leaks after that. 

What solution are you using as your leak detector? Make sure if using soap and water that it is very bubbly by shaking the solution up before spraying, and make sure it’s coming from a fine mist sprayer. 

Another good product to have on hand is CRC leak detector. It comes in a pressurized spray can and shoots a foam solution out that will form large thick bubbles around most pesky leaks.

If all else fails, you can do what myself and some have done, and that’s to remove the scope, stock and dunk your gun in water, looking for the bubbles. I prefer a five gallon bucket vs the bath tub as my thought is I may find the leak coming from the front part of the tube, the area I will dunk in first. No reason to get the gun all wet if I can help it. If you do end up getting the gun all wet to find the leak, it’s a good excuse to freshen up the gun with fresh lubes after you’ve dried up all the parts thoroughly. I recently went thru this with my Impact.



when refilling your gun from empty always do it in stages. Slow stages. Barely crack your tanks valve. I fill slowly to 100 bar and stop. I’ll wait five minutes then fill slowly to 180 bar, then stop and let the pressurized cylinder cool off again. Then from 180 slowly to spec fill, and I’ll go past spec fill by 10 bar, so when it cools off it’ll fall right at the spec fill.
 
Air is escaping thru the vent hole in airtube. Reg orings are probably the 1st ones I'll address.

Just had this issue with a friend's Mk1 .22 Wildcat. If gun is depressurized, unscrew the pressure tube (you can't unscrew this one with pressure on it like a Bobcat.) Unscrew the end cap, remove the spacer and reg assembly. Remove the reg from the fitting it sits in. Replace the outer two orings on the reg (11.6 x 2.4mm 70 duro), then replace the two outer orings on the fitting that the reg sits in (23.3 x 2.4mm 70 duro - 23 x 2.5 works also just fine). I'd also replace the one oring that is on the end piece plug (23 x 2.5mm) that you unscrewed to remove the reg assembly. Lightly lube with silicon grease all orings and reassemble. Should be good to go. Hopefully you don't have an internal leak with your reg, but this is a quick easy job, try this first before you start taking apart and messing with the reg internals.
 
Bigragu thanks for all the help and information. In fact after the latest fill I did do a slow fire with the Hades pellets and the JSB 34'3 just to see what speeds I was getting with the regulator setting on the Huma. Early on in the trying to track down the leak I did use soap and water of the ends of the tube and found a leak on the fill end of the tube. That was when I replaced the o-rings on both ends and the dowty seal. Today I did a slow fire again to see if that would work I guess for maybe trying to get the valve seat to settle as a potential problem. At this point after 12 hours it seems the pressure is holding. Centercut I did at one time have both the Huma and fx factory regulator leaking from the vent hole. In the case of the FX regulator I replaced both the inner and out set of o-rings but it still leaked from the vent hole. I do think in addition to using silicone oil instead of silicone grease and in the right amount makes a difference but what Bigragu said about filling up in stages could be beneficial. At this point I am still willing to trying working on the Wildcat to get some experience and since I have other rifles to shoot. Thanks Bill

PS I am going to get some of that CRC leak detector
 
So I ended up sending to Mike at Tko airguns. He's helped me out in the past w other airgun related issues and designing ldcs to quiet them down. He's also the original designer of the Prod trigger mechanism which I never knew. Anyway, he was not able to get my Wildcat to totally hold its air pressure. He had it for atleast 2 months .Changed virtually all the orings and had the regulator all apart. He didn't charge me a penny for his time because he took his failure to solve this Wildcats issue personally. I ended up selling the gun as is for $550. I loved my Wildcat but after this I can't look at any Fx Wilcats the same.