My 6cu ft 12V, 110 swing motor compressor type has a small leak. I have a low side service port where I have added dura cool and got it working, is there an optimum low pressure number?...

And another thing. It was originally charged with R12, so you charged it with Duracool 12a, right? Not 22a?

Yes, Wally has his boys look at it last year, they added the service port and got it working. They charged it with real12, when it got low, I just added dura cool. So it is a mix. I got a hunch I got it over charged as the low side was bout 30. I was rethinking 0-10 maybe.

You guys are really confusing two different type of refrigerators. The compressor type uses R-12 while the other one is an absorption one using ammonia and a completely different cooling system.

On the R-12 one the pressure determines the evaporation temperature point. The lower the pressure the colder the box will run. If it has a freezer then you want it to maintain about 0 degrees F in the freezer. I just looked at the pressure chart for R-12 and it says you want about 9.1 PSI to the evaporator for pure R-12. I then looked at a chart for Duracool and it says a pressure 0 PSI will give you -9.76F while a pressure of 7.3 will give you a temperature of +8.6F. So for pure Duracool you want something somewhere in the middle between 0 and 7.3 PSI.

Since you have a mix of R-12 and Durcool I would guess that you want something less that 9PSI to start with and reduce it as necessary from there until you get the operating temperature that you want.

On the absorption one you could try putting it upside down for a while to see if it frees up any clogs or gas trap and then go from there. Normal repair procedure is to replace the entire cooling unit. You do not install a service port or charge an absorption refrigerator with Duracool or R-12. It has an ammonia based refrigerant and works on an entirely different cooling principle.

My my freezer thermometer suggests 0F as ideal temp. It also suggests 36 to 40 as ideal in the refrigerator. So that is where I run them.
From the Internet:

-18° C
Keep the refrigerator temperature at or below 40° F (4° C). The freezer temperature should be 0° F (-18° C). Check temperatures periodically. Appliance thermometers are the best way of knowing these temperatures and are generally inexpensive.Jan 20, 2015

Forgot to ask. Can you post a picture of the low side service port?

http://www.gmcmhphotos.com/photos/member-galleries/p58256-fridge-service-tap.html

I have been working on a Norcold DE726 out of a 1973 Sequoia off and on for the past couple of weeks. Nothing really wrong with the mechanicals, but the bottom trim plate on the door was rusted away and the door seal/gasket distorted (partly because of the rusted trim plate, partly from a wasp nest that the door was closed on for who-knows-how-long, and partly from a PO that tried to glue the gasket in place with what appears to be PVC cement). Unfortunately, the door gasket is pretty inflexible from decades of sitting in a hot vehicle, and I am not having much luck straightening it out. The door panel had been vandalized by a clueless brat with a spray can. And I still have to figure out how to get that PVC cement out of the gasket groove.

Got the door panel sanded smooth and painted with white semigloss interior latex (that's what I had on hand, and what I have to use since the CFO stopped cut off my GMC allowance). Used some creativity and painters tape to get a reasonable door seal for testing purposes.

Brought it in from the carport where it was about 85F to the house where it is 75F, set the thermostat for 3 and plugged it in. An hour later the fridge was at 55F and the thermostat turned it off. I just turned it down to 4 and it started running again. Will let it run until the thermostat turns it off again and see how long it takes and what temp the fridge is at then.

A Hamilto wrote on Mon, 29 June 2015 13:20

I have been working on a Norcold DE726 out of a 1973 Sequoia off and on for the past couple of weeks. Nothing really wrong with the mechanicals, but the bottom trim plate on the door was rusted away and the door seal/gasket distorted (partly because of the rusted trim plate, partly from a wasp nest that the door was closed on for who-knows-how-long, and partly from a PO that tried to glue the gasket in place with what appears to be PVC cement). Unfortunately, the door gasket is pretty inflexible from decades of sitting in a hot vehicle, and I am not having much luck straightening it out. The door panel had been vandalized by a clueless brat with a spray can. And I still have to figure out how to get that PVC cement out of the gasket groove.

Got the door panel sanded smooth and painted with white semigloss interior latex (that's what I had on hand, and what I have to use since the CFO stopped cut off my GMC allowance). Used some creativity and painters tape to get a reasonable door seal for testing purposes.

Brought it in from the carport where it was about 85F to the house where it is 75F, set the thermostat for 3 and plugged it in. An hour later the fridge was at 55F and the thermostat turned it off. I just turned it down to 4 and it started running again. Will let it run until the thermostat turns it off again and see how long it takes and what temp the fridge is at then.

It got down to a little under 50F at a setting of 4. Turned it to 5 and it eventually got down to 40F plus or minus (39.7 to 40.1). The thermostat calls for cooling at 40.1 and shuts off at 39.7.

The freezer is still getting colder with time. Every time the thermostat calls for cooling, it is a little colder than the last time it called for cooling, and when it shuts off, it is a little colder than before. After a little less than 7 hours of cycling, the freezer is at 13.3F.

It appears if I want the fridge a couple of degrees cooler, or the freezer colder, I would have to replace the thermostat.

You have been more successful than I. I got it stabilized to cool the freezer to about 15°F, but I wanted better. I ran out of time and tried first one and then another dorm reefer run from a modified square inverter, and Mary likes the second too much to even think about putting the old NO-Cold back in.
Matt