Last year I bought a late70's? coke machine in mint cosmetic condition from a elementry schools teacher lounge where it has been its whole life. Took her home and in my garage I pluged her in and the ciculating fan came on but no compressor. So I bypassed the thermostat (connected the 2 wires together) and compressor turned on and cooled the unit down to 30 degrees in under an hour. So I purchased a new thermostate from a coke machine dealer online and installed it. Now with the t-stat installed it will not cool below 50 degrees before it shuts off and then turns back on at 57 degrees even with the thermostat is on the coldest setting. The compressor at this point is blazing hot so I think it is shutting off and on due to the thermal overload. The condensor is clean and not cloged. Do I need to get this recharged?

I know there are some refrigeration techs out there please help my cokes are getting warm.

 

You could be low on freon. Short cycling is definately a sign of this.
Check any coils inside and make certain they are not iced up, blocking airflow and any fans are working properly. If its the first humid weather since you got the machine this could be the problem.
Check to see if it has a defrost timer, and make sure its working
Maybe your thermostat has gone bad again. It wouldn't hurt to test again.

 

Did the comp. get hot when you jumped it past the t-stat?
Check for any signs of the compressor being replaced or anything else for that matter, If the compressor has been replaced due to the last burning up, then it could have some trash in the system and it can clog up a cap tube or the strainer for the ecpansion valve.
Check to see if it's an expansion valve or cap tube system.

 

The coils inside develop a thin layer of frost on them. I will have to make sure they are not developing enough to clog airflow. The fan to circulate the air inside the machine is working properly (Always on) as well as the fan to cool off the compressor (on while compressor is). How do I tell if it is a an expansion valve or cap tube system? I can rebuild anything on a car/truck so I don't want to let a little coke machine kick my but.

 

Have you checked the t-stat for adjustment that should be the only thing that is wrong it should shut down at about 35 and come on at about 40. Is there a presure control on the system. Can you pm me

 

I've been around enough refrigeration systems to know that they are best left to the professionals when they need work on the sealed part. Refrigeration gas is expensive and you need specialized tools to do a proper job.

I scrapped a coca-cola fridge that blew a compressor after I was quoted $500 for repairs.

If your getting frost on the coils, then try unplugging it and propping the door open for overnight or for a day or so. This should thaw everything out. Look for puddles that would indicate that something thawed out. Plug it back in and see if it works. If it gets cold and works fine for a few days or a week then its the defrost timer.

A quick and nasty way to fix this is to put a light timer on the outlet that its plugged into and set it to turn off for a few hours every day ( 2 am-4 am or so)
Of course you dont want to keep anything in there that could spoil easily and make you sick, but your average frosty beverages should be fine.

 

Depending on how old this unit is it may not have a defrost system at all. Many were made to run almost all the time and defrost the coil when the control shut the comp down. I do this for aliving. If you can provide me some more info like make model and year of the case and the comp I maybe able to get you some really helpfull info.