I am in the process of rebuilding my AC system on my 1990 twin turbo Z. Rebuilt compressor, new drier, new expansion valve, new pressure sensor, and changed all o rings. I vacuum tested the system and everything looked good. When filling the the system with R134, I discovered, that the sight glass was leaking. I was able to get the sight glass out, but it got damaged during the process. I can't tell what kind of seal was in place below the sight glass and have not been able to find any information on it. I have two questions:
1. Does anyone know where I can find a replacement sight glass or what other car has the same sight glass that I can get it off of?
2. What seal should I use to seal the sight glass?

Any info would be greatly appreciated.

I will have a look at mine tomorrow

Hi I had a look there is a paper thin gasket under the retaining ring that crumbled when I touched it glass did not come out, there looks like a black O ring behind it but that one & the paper one does not come with the refresh kit for R134 or is mentioned in the manual.