EDgun Lelya 2.0 Mystery Leak

After shooting my Lelya the other day I put a little silicone oil on my fill probe o-rings, rubbed it in to the o-rings, inserted the probe, aired up my Lelya some, and set her down expecting to go out the next morning. After I dressed and got ready to head out the next morning I checked the gauge on the reservoir and it was around 75 bar. The gauge never gets that low. 


I double checked my log and saw that I had aired her up to around 175 bar the night before. I aired her up again to 185 bar and debated on whether I should take her out. I decided to go and didn’t have any issues with leaks. In fact it hasn’t leaked again since - today is the third day. I’m wondering what causes this sort of leak. Could it be a valve? It doesn’t appear to be a slow leak because I would have thought the reservoir would have lost the same amount of pressure by now. The gauge hasn’t moved much. Last I checked it’s at 180 bar and the 5 bar could have been me reading the gauge from an angle (I don’t like putting my face in front of the barrel). There are no 5 bar increment marks on the Wika gauge so if the needle looks to be in between two 10 bar marks I call it 5 bar. 


I read about placing balloons over both ends of the reservoir to detect slow leaks where o-rings have degraded. I haven’t tried this. I’ve also seen a video of how a fill port leak behaves. It doesn’t seem to be a fill port issue. I’m just confused as to why this occurred so rapidly overnight on one occasion and nothing similar has occurred since. Any ideas? Could a little silicone on the fill probe o-rings be the culprit? I’d appreciate some help here. Thanks in advance for the assistance folks. 
 
Remove the air tube and dunk it in a tub of water. Find the leak and fix it... It will not harm the gun. Make sure there is air in the air tube.

You may have drug some contaminant in with the fill probe and are now losing air from the fill probe check seal.

Dunk it. No need wasting time trying to find a potential leak. If you dunk it you will find it👌
 
I never lube the probe orings for this exact reason. Now you’re just begging to drag a hair or piece of debris in there. Orings are cheap so I don’t concern myself with replacing them. I have probes over 5 years old that I never lubed. The one for my BSA Ultra might be approaching 10. I do keep them in old medicine containers to keep them clean. Hopefully your gun will be ok and not require any disassembly.
 
I never lube the probe orings for this exact reason. Now you’re just begging to drag a hair or piece of debris in there. Orings are cheap so I don’t concern myself with replacing them. I have probes over 5 years old that I never lubed. The one for my BSA Ultra might be approaching 10. I do keep them in old medicine containers to keep them clean. Hopefully your gun will be ok and not require any disassembly.

I’ve read pro-lube posts and posts to the contrary. I think the attracting dust and debris arguments are valid. I do keep my fill probe and fill adapters covered in plastic when not in use for the most part. However, I’m still not sure if that created the issue. This was a weird instance. So far I haven’t found much info on similar situations. 
 
Hopefully the little culprit got blown clear when you had to refill it. I think when a PCP guy sees an oring, he just feels obligated to lube it. I look at it like this. What are you trying to accomplish vs what do you want to prevent. I want my fill port as clean and dry as possible. Now we wait for the guy who has been lubing probe orings since they were invented to chime in he’s never had a problem. It’s just my take on lubing them, definitely not gospel.