Freon charge

I have been reading in this forum and have a question on freon charge.  The box I am working on has a tag that states 8.5 oz.  The box was worked on about 6 mths ago, but that company has closed, so I have been working on it now.  The first time I worked on it, the gauges read about 0 to 2 lbs on the low side.  I put R12 up to about 12 lbs on the guage and it cooled good for about a month or two, then it got warm again.  I put more R12 in it to about 16 lbs on the guage, it cooled very good over night and then it quit, the gauges read about 5 lbs.  All of the time I was working on it, the entire 2 months the small line would freeze up.  So I decided to pull a vaccume on it and start over.  I pulled it down to 30" and let it set 24 hours, and the gauge still had about 29" on it.    
I put Freeze 12 back in and after about 6 oz I was still reading a vacuum, so I put all of the 12oz can into it and still had some vacuum.  Should I still have a vaccume or pressure, this is the first coke box I have worked on if you could not tell.

[Kevin C]

Hello

It sounds like you have a restriction in the refrigeration system.  

I would recommend that you call Eric at global compressors. He one of the sponsors of the website.

Kevin