no there's no o-ring on the fill valve.

umm yah there is... there is a small one on the inside and a larger one on the outside. With these I find that I need to soak my fill valve the night before or they piss gas. *soak on oil* also fill in short bursts or the valve will usually end up sticking. If its pissing gas while filling I normally rotate the bottom or the nade and that tends to great a better seal.

In short
yes Oring
Yes leaky when filling


PS I would snap you a pic but it appears that my fill valve is freaking stuck... ironicly I bet its the oring lol
PPS got the valve out. I apologize for the blurry pic but the oring at the tip of the tool sits around the fill valve.

he's talking about the external; where the adapter goes to fill the grenade. My 3 grenades don't have one EXTERNALLY... they all have one internally - that only makes sense...

Yup.

ah ok I thought you ment external as in on the outside of the fill valve... Not the outside of the nade. My bad.

i just picked up the Impact Grenade and posted the same question here. When filling i get a venting after a couple of short fill bursts. I am not sure if it's filled all the way and simply venting any over fill.. or if it's actually leaking right out of the box. .brand new ..

At first i used Green Gas with a metal nozzle and now i'm using the same Madbull metal Propane adapter.. both have caused this venting. Could it be the metal fill stems in these types of adapters?

I had a defective AI impact too. Maybe they got a bad batch of valves...

I have contacted AI before taking anything appart and they sent me a valve for free.

Also metal adapters break valves. Get the tan AI one, it works great.

The AI grenades fill from empty in about 2 seconds. It will spray a small cloud when full.

Make sure you have reset the shuttle, installed the pin/plug (timer version) and screwed the top properly before fill.

Also, you should not need to use anything but your hands to open/close the top threaded portion. It's not supposed to be on THAT tight.