Hey guys,

Great help in the past and hopefully this time as well. Anyway, suppose you convert your old timey freon to 134a and have it evacuated, how many 12 oz cans of freon would it take to get it to the proper level on average ? Or how many ounces would it take to fill er up ? I really don't need anything scientific, I just want to have a ball park range. I don't want a guess, I want something close.

Have a good weekend and thanks for helping.

 

maybe two twelve oz cans (or three, but doubtful) with some o-ring conditioner as well

 

What year?

 

To answer your question, I have averaged 3 to 4 cans on my 1986 model trucks. I will add a little extra(advice, not freon LOL) too even though you didn`t ask for it. Keep in mind there are other issues/factors to deal with here when converting from R-12 to R-134A, if you want your system to last into next year. One, R-12 and R-134A o-rings are made of a different material, they will all have to be changed (at least they were when I did my vehicles). Two, the compressor will have to be flushed (not with water) and cleaned along with all associated parts and hoses. Three, new accumilator (dryer). Four, new and correct orifice tube. The compressor seal may need to be changed also. You will need to pull a vacuum on the whole system when done to check for leaks and remove moisture before adding your 134A. There is also a check valve on some systems located by the passenger side of the radiator in the hi-pressure line that can get plugged up with metal shavings. I have had 1986 trucks that had them and some that don`t, go figure? Unless you have all of the right tools, know-how and specs, it is best left to a professional. Not to say it can`t be done because I`ve done a few of them with excellent results. This is my own opinion as I am sure there will be contradictions of what I just said. What doesn`t work for some, may work for others.

 

Another thing I forgot. The whole system and components will need the proper type and amount of refrigerant oil added back into the system after flushing. Hope this all helps.

 

78 to 96 take different amounts, did I miss the year? Hort is right but IG conversions don't require opening up system, only replace o-rings at inlet to evaporator(quick disconnect fitting) also pull out orifice with long needle nose plyers.If it is nasty- black looking sandy particals packed on it, flush and new accumulator are needed, if it is pretty clean replace with new one.Converted my 78 and just recovered- evacuated- recharged- added dye and been great (2 years and running) Usually NOBODY converts a good working r12 system- I have been working an ac for 27 years and what works for- say one 86- may not work the same as the next 86-Like Hort- FIND someboby who KNOWS what they are doing or you may end up working on it more than once!!!

 

Thanks for your advice guys. I am familier with the replacement of the correct parts and stuff, I just wanted to know how many ounces it would take to fill her up to proper specs or what not. Great info and I'll let you know the results.

Thanks again guys,

 

PS older systems used high pressure filter-dryers and expansion valves and water cut off valves de-icer (therm switch),newer ones (started in early 80s) used low pressure accumulators, fixed orifice and elec. cycle switches and blend doors.Freon leaves compressor goes through orifice ,(caught any gargage), then to evaporator out to accumulator and back to compressor. Fast cycling compressor is normally low in freon BUT a stopped or partialy stopped up orifice will appear exactly the same!!

 

I ended up using about 40 oz of R-134 in my 86, when it called for 52 oz of R-12. This gave good gauge pressures, and it's cold. I didn't change my orfice tube, and it goes down to about 45 degrees at the vents - I'm happy with it. I did change all seals, blow old oil out with compressed air, and use 10 oz of ester 100 to do the conversion. I also replaced the accumulator and adjusted the pressure switch 1/8 turn counterclockwise.