After replacing all the gaskets in my 3rd series Faema Faemina, I discovered a very small leak from the sight glass.
First I want to know if everything is normal- when water present in the boiler you can see them in the sight glass? I guess this is what the sight glass for.. but it seems strange that the spring is sitting cover with water.

I put the new sight glass gasket and ring from Francesco, and close the lid by hand. Do I need to tight it with pipe wrench? does the gap in my sight glass normal? The glass is not original, but it's 3mm thick par to Francesco.

does it leak under pressure or already without? Afaik the bezel needs to be tightened more than hand tight but not overly tight. What gasket did you use? Some of the fibrous gaskets leak a tiny bit initially.

It leaks while machine at rest. In the first few days it wasn't leaking, then I used the machine for few days (2 espresso per day) and after 3-4 days I notice the leak. It still leaking now, even I didn't use the machine for few days.
I used 2 gaskets, one is black and one is green. Seems like the green is fibre?

the green is indeed a fibrous gasket, are you sure the gasket seats are perfectly clean? Tiny specks of dirt may prevent a good seal, so does loose fit, did you try turn the bezel a bit more?

Did you put the fiber gasket to the outside, and give both a light application of grease? The bezel should be just hand tightened, and make sure all surfaces are clean and smooth. Also check the glass itself.

I didn't recall applying light grease to the gaskets. The fiber gasket is the deeper one. Since my hands are not that strong I tight it a little bit more with wise grip last night. I hope it's not to tight now. No leak since then, But I need to continue using the machine in order to determine for sure.

If I need to open it again I will apply grease. I don't know how I skipped it, I usually do so.

if it;s a slight leak this should work...or you will find out!

Did you replace your sight glass. I need to get a new one. Any suggestions on where to get a sight glass. Thanks

No. I just needed to tighten the bezel a notch or two.