Pepsi Machine, Vending Machine compressor
 

I have a 1980's Pepsi machine and the compressor was replaced a few years ago with I believe a R-134A but I don't know for sure cause I have only owned it for 8 months. The compressor yesterday stopped running. I can hear all fans running but the compressor will start up for about 4 seconds and then stop and will try again every so often. Does this sound like it is just in need of freon or is it a bigger problem? I am not very knowledgeable in the mechanics of a compressor so sorry if my lingo is off.

Welcome Wristie:
Your unit was built before the advent of R-134A and probably has R-12 in it. I lean toward a defective high pressure limit switch or a kink in a refrigerant line. The problem is called 'short-cycling' and is normally caused by high head pressure (the compressor can only pump up a certain pressure and must shut off to allow the refrigerant to equalize pressures on both sides, then try again).
Glenn