Cup seal?

[Paint Bulley]

What's the cup seal look like?

Isn't it the little white thing, by the spring?

I got a spyder if it matters.

If I can hear hissing around my valve (in that area) do I need a new cup seal?

It was hissing a lot. then I tightened my valve screw and it slowed down.

Need help.
Thanks,

[blake_sw]

Ya, it's a little white plastic part that's located next to your valve. Make sure you NEVER scratch it, get it dirty or damage it. Check the surface for any damage, if there is some, you'll have to replace it to get rid of the leak. I suggest a Lapco cup seal, they're much better than stock ones.

[DraXsuS]

sometimes u cant see the damages on the cup seal