A/C Chil-rific

[brian_wagner at sbcglobal.net (Brian Wagner)]

Allyn,
 
To answer your question on how I achieved these great numbers, is I don't know (jk).
 
First of all the keys to a good cool system are as follows
 
1) Remove all R-12 and flush the system (both condensor and evaporator, don't flush the compressor it can damage the valves)
1) Replace the Receiver/Dryer
2) Replace the Expansion Valve
3) Replace orings at all the joints
4) Draw a vacuum on the system (- .8bar(-10~-14lbs), remove the vacuum pump and let the system sit 10minutes to verify system integrity (ie no leaks and it hold the vacuum).
5) Put in R134a ester based oil that will work with the old R12 and oil 4.5 to 6 oz(PAG oil should only be used on systems were the compressor has been replaced and the system been flushed). I usually go 6 oz, it will be sucked out of the can since the system has a vacuum drawn on it.
6) Now put in the first can of R134a (I like Dupont Suva with UV dye), the compressor will not kick in until you have 10psi of pressure in the system. If needed you and jump the low pressure switch to turn on the compressor to aid in putting in the R13a (shouldn't need to).
7) Put in the second can and the compressor should be on at this point, and finally the 3rd can (you may not need the full can, read the following).
8) This is where you start to watch the head pressures, low side should not exceed 40psi and high side needs to be below 225. These pressures will be indicative of how well the system was cleaned, the more gummy the system from old the higher the value. My system runs 15psi on the low side and 160psi on the high side.
 
 
Does this help.
 
Brian