Why is my MR-1 leaking like a siff?!?!?!

[Stryx]

I recently got the MR-1 and after one day of play it is leaking air. I pulled it apart to check the o-rings and they looked fine. After I put it back together it was leaking worse hissing bad where the bolt is. Anyone know why this is. or what I can do to fix it?

[kidonfire]

Sounds like your cup seal or an o-ring on your valve is bad. try replacing the o-rings on your valve and if that doesn't work, replace your cup seal. One question though. Have you tried cocking the gun before you put your tank on? It might be that the striker is pressing too hard on the valve pin opening it up a little.

[oldironmudder]

Like KOF said, cock your marker then put air to it. The check your cup seal & valve orings.

[Stryx]

With the bolt cocked it was still leaking. I looked at the cup seal and the valve pin. The pin is rounded on the edges where it is flat. Could that also contribute to that? The cup seal looks good also. Thanks for the help.

[oldironmudder]

The pin is good. Since it is a new marker, it should have come with a new cup seal. Put that on the pin, they simply screw off& on. But before you do that, look at the sealing surface on the valve where the cup seal sits.

[Stryx]

Got it, I put the small shim that was with it and changed out the cup seal. That stopped the air leak. Now I know where to look if it does that again. Thanks alot for the help.

[Critical]

Another thing you can do is take some fairly high grit sandpaper (I've used 600) and lightly sand the flat of the cup seal.

[Kenny_McCormic]

Polish the sealing face so the cup seal doesn't have to work as hard.