Mercedes: 1995 Mercedes C220 A/C, receiver dryer, ac unit

Question
I had my ac unit charged with freon and the repair shop put dye in the system to reveal any suspect leaks. The system held up for a month and a half and then it went empty. I saw the green dye coming out where the ac view glass is toward the front of the car. The glass was cracked and the fluid was coming out there. What is this part called? Thanks,

Answer
Alfred,
The site glass is usually part of the receiver/dryer/accumulator. You should be able to get a replacement part through an AC parts supplier. You will need to have the  system vacuumed and freon installed. The glass allows one to see the the circulation of the freon during the cycle.
If the part is installed with nut type fittings to the hoses, be sure to get the correct seals. The seals will be different if the system uses 134A as opposed to R12.
Good Luck. Let me know if you have any questions.
Robert