Tip & How-To about Refrigerators

Refrigeration and Absolute Vacuum

I have noticed some good advice here when it comes to pulling a vacuum and recharging a refrigerator. I also have seen some not so good response to answers when it comes to someone that is new to pulling a complete vacuum. *Refrigerators and absolute Vacuum are about the most difficult combinations to obtain. First mankind has never achieved absolute vacuum and the closest we will come in our life time to complete or absolute vacuum is in outer space. When repair is done to a sealed system there are a few things to remember. 1 Once a sealed system is opened never leave it unsealed to the outside environment. Most new refrigerators have ester oil as a lubricant and ester oil will draw moisture from the air and hold it in the oil resulting in the oil carrying moisture particles up the capillary tube and creating a blockage that appears as if the suction side is pulling a deep vacuum. 2 Always replace filter drier with a new filter drier and arrow pointed into the correct direction. 3Always find and fix a leak in a sealed system before recharging. * Some leaks are in the Yoder Condenser Loop and the only way to fix is to bypass. This will sometimes show up as sweating around the door frame but much better to deal with than complete refrigerator replacement. 4Pull a vacuum as long as it takes to boil off any moister that may be trapped in the sealed system. If system has no leaks and you use a heavy duty vacuum pump this is about a hour. 5Always test gauges for leaking seals in gauges before spending so much time pulling any vacuum. *Bad gauge seals will result in moisture or poor vacuum results. 6Always charge refrigerators by weight. *Refrigerators use very little Freon. 6-8 ounces, over or under charging will result in poor cooling results all the time. 7Never try to solder steel to copper piping with just silver solder. * Always use eutectic solder for soldering copper to steel. * In this case eutectic solder is defined as Flux-Coated Silver Brazing Alloy. For example Safety-Silver 45 by Harris. 8Always use the correct oil for the correct refrigerant. * Too much, too little or wrong lubricant will damage the system. If you have questions please let me know, Thanks, Sea Breeze Here is more....... As we talked earlier I did some research on Fijitsu Split systems and as always with these units they is very little in instructions or model/size category to give good solid answers to all the possible problems you may be having. I do know with my experience that the R410A are critical during installation that they havea very good and long vacuum during pre-charging the lines during installation. One little bit of outside air in the lines will cause extreme head pressures that will also simulate some of the symptoms you described today. R410a runs at 60% higher pressure that the older R22 units did and purge and clean silver solder of fittings is critical to the unit's performance. Even a crimp in a discharge line makes for problems during installation. here is a link=> Brochure here=> http://www.fujitsugeneral.com/PDF_06/halcyon06_brochure.pdf If you need more answers feel free to contact me here or through my profile and again Thanks for using Fixya, Sea Breeze

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2 Answers

gdm 45 with new thermostat goes down to 28 degrees and compresor does not shut down


If the new thermostat sensor is secure and where it belongs, it has the wrong charge in the system. That cooler takes a critical charge. The factory charge is in ounces if refrigerant. The system needs to be evacuated completely with a vacuum pump and recharged with an accurate scale that weighs in ounces. That will solve your problem. A refrigeration tech carries the necessary tools that an hvac tech doesn't. Hope this helps and good luck.

Apr 13, 2014 | True GDM-45 Refrigerator

1 Answer

were to add refrigerant


If you have to add refrigerant you have a leak & need to have to system leak tested and then repaired,vacuum pulled & recharged. You need a shop that does A/C work,no way to know how much to add without knowledge & proper equipment.Be responsible & don't polute the atmosphere doing your own a/c work

Jun 05, 2013 | 2003 Dodge Intrepid

1 Answer

I have not recharged a system in a while. If the system is out of freon will the compressor still turn to pull in the refrigerant.


It should take the freon . Compressors will actually pull a vacuum if the refrigerant
is completely exhausted. You should be able to recharge system if the unit is just low
on refrigerant.

If no pressure is in system, I would have the accumulator replaced and
have a vacuum pulled on the system before recharging it. (The accumulator has a
dessicant/ filter in it and may become clogged if the system is empty)
The vacuum is to boil off any moisture in the system
from having it open and also to check for leaks. If moisture enters the system because of a leak then it can freeze in the metering
device when the system is recharged. I hope this helps.

Jul 23, 2011 | 1999 Buick Regal

2 Answers

how do you evac and recharge a true freezer compressor??


Your unit takes R-134A you can buy that anywhere it is 0 depletion on Ozone. The hard part is getting access to your lines if you have a service tap installed piece of cake. They make a saddle valve you can install to access line set. Pull a vacuum on unit takes a vacuum pump and about one hour of running the vacuum. Just put one line tap on the line and be sure it goes on the low pressure line not the high pressure side. The unit the fridge only takes about 5 ounces of refrigerant and has to be weighed in. Also has to be put in as a liquid as this is a blend of refrigerants. As long as you have gauges and pump and a scale I can walk you through it step by step get back with me and we can do that. ken

Jan 11, 2009 | True GDM-41 Refrigerator

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