Coke Machine

[srh]

I have been reading in this forum and have a question on ***** 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.

[Brian_UK]

Please don't use R12...it's bad for our health.

Have you checked the filter/drier, TXV or cap line.

Are you saying that you still had a vacuum after adding the 12oz without the compressor running or was it with the compressor running.

I thought Coke machines were serviced by Coca Cola themselves or is it a "pre-owned" model?

[srh]

The vacuum is with the compressor running.
I have changed to Freeze12 now.

[afeef]

leaving the machine on vacuum for 24hr.is not enough,,,
there is some leakage need 1 or 2 weeks to varify,,
put the machine on 300 psi netrogine ptessure, and check leakage by soap after 3 hours.
good luck

[Bones]

Yes, i agree with afeef.

charge system with nitrogen and start looking for the leak with .05c soapy bubbles

[Abe]

He said he pulled a vacuum, then left it idle for 24 hours, still had 29g vacuum in it...

So.........No leak

I bet its got a restriction.......
and..........

I dont think this guy has a clue.....
So he better not mess around with nitrogen.......

[Brian_UK]

I dont think this guy has a clue.....
So he better not mess around with nitrogen.......

Damn, you spotted it Aiyub

[srh]

Well I use nitrogen to test with at the place I work all of the time, so I know what pressure is and can do. This is the first Coke box that I have worked on, so you are correct that I have no clue on how to fix it, but I am not completely stupid.

Still have not got the answer to my first question, will it still show a vacuum when it is fully charged?

sh

[chillin out]

Still have not got the answer to my first question, will it still show a vacuum when it is fully charged?

Hi srh,

No, the system will not run in a vacuum under normal working conditions.

As said by Aiyub and Brian you most probably have a restriction.

chillin

[Cofreth]

Probably a choked strainer or capillary tube, replace a new strainer and reverse purge the capillary tube with dry nitrogen gas.

[Abe]

Well I use nitrogen to test with at the place I work all of the time, so I know what pressure is and can do. This is the first Coke box that I have worked on, so you are correct that I have no clue on how to fix it, but I am not completely stupid.

Still have not got the answer to my first question, will it still show a vacuum when it is fully charged?

sh

Who said you were stupid??

What was deduced is that your prognosis ability left the impression that you were inept, and handling a high pressure gas like nytrogen in that circumstance woulod probably be dangerous.

And if you do WANT to be helped by fellow members, then perhaps an "attitude" will not help your cause.

Remember, we are here to assist and help those willing to recieve it, and where safety is concerned, will not flinch from saying so

Have a good day and a pleasant stay in RE

[2002kahuna]

Vacuum will not always show small leak in system. Pressure will show leak faster and more accuratly. Use trace amount of refrigerant(1 oz). Pressurize system to 150 to 200 lbs with dry nitrogen(check system rating on system plate).
A drop of water the size of a pinhead will freeze solid in a cap tube and cause suction to got into a vacuum, and head pressure to rise quickly. Is your head pressure going high while suction drops into vacumm?
Either way it sounds like you have something restricting your metering device.
On small system like this it is best to weigh in your refrigerant. You can do frostline charge but let the system work. You can't hurry it.
Depending on what refrigerant you are using when your are done your suction pressure should be somewhere around 0 to 5 pounds. Don't hurry it. Let the unit work, with a cap tube it will take the system time to level off to normal operating conditions.