5 replies to this topic

[jyarosz]

I have a Dixie narco 348 soda vending machine.It seems to run constantly,and the eveperator ices up in the corner and the small freon line that enters the everaporater.The door seal seems to be in good shape.I think it may be low on freon? I have a piercing valve and freon.(R12),and gauges.I'm not sure how much freon it holds and what kind of pressure I should have on the low side.Also can I tap the dead ended line where it was originally charged or should I tap the line from the compressor to tha evaperator.Thank's for any advice.

[djpvending]

are you sure it is r12?....yes the symptom you describe is an indication of a leak......if you do add freon, this may only be a temporary fix...the leak will still exist...when freon leaks,it will get to the point of being replaced by air....which with humidity in the air can cause further problems.....also with a piercing valve and guessing at freon....is rolling the dice...if you choose to do this i can tell you that as you charge....disconnect the evaporator fan and charge until you get a frost line that stops 2-3 inches beyond the heat exchange on the suction line coming out of the evaprorator.....you must be very patient using this method adding only a little at a time....i hate to even suggest this method,,,unless in all due respect you are very experienced in working with refrigeration....

the right thing to do, with the proper tools, is pull the unit....sweat a charging port on, evacuate, find leak, repair and with a set of gauges get the low side to 15.....which should put the high side at about 150, depending on the ambient temperature of the room the service is being performed in....

side note: yu will have a very hard time finding anyone to work with r12 in vending........134 is the common replacement......might be better off finding a replacement unit...

[jyarosz]

Thank,s for the reply.The compressor has R-12 printed on it.I used a pierce valve on the low side,the unit only had about 4 psi while running.I added some freon to bring it up to 17 psi and the unit is working perfectly.I checked around with a leak detector but couldn't find a leak.I'll keep an eye on it for any problems but right now it works great.

[djpvending]

hmmmm......well ones thing for sure, you have a leak somewhere.......hopefully it is an extremely small one....it may last a day....it may last a couple months.......but at least you have bought some time to decide whether to pull the unit and have the leak found, or possibly find a used, working unit to replace it with......i know yu are trying to save money, but sooner or later you will have to deal with it....

good luck!

[jyarosz]

Well it's been a week now and the machine is still running great.Pressure hasn't dropped and I've been all over it with a good electronic leak detector.Must be a very small leak.It's keeping the product right at 38 degrees.Only problem now is once in a while it gives away a free soda.I'll have to study the print and see what could cause this problem.

[validatorman]

We repair 100's of these decks and we actually dip tank the units with Nitrogen in them to find any pinhole leaks. The evaporator often has leaks that are very small. RB420 is a drop in replacement for R12 as it is compatible with the oil. If you put a tapping valve on and leave it you are just asking for trouble. Those units usually have a 8.25 - 9.5 charge, a little less than specs if you go with RB420.