91 AC change over questions
07-05-2017, 04:25 PM
#21
I did my retro last week and reused my 30 yr old condenser after flushing it and it works great with ecklers retro kit. The difference is the orifice tube is slightly different to make up for the different refridgerant.
Good Luck
Good Luck
07-05-2017, 06:09 PM
#22
Melting Slicks
My condensor was badly damaged so I have replaced it. The evaporator was removed cleaned and flushed along with the condenser. New o rings and r134a charging ports. New filter dryer. I plan on putting 8oz PAG oil in the system. Do I need to get oil out of the compressor. I don't see a sump or anywhere to add or drain the oil. Do I need new pressure switches? if so which ones. Lastly, the original capacity was 36 oz. of Freon. I have heard we should use about 10% less R134A. The roadster is not exactly air tight and living in East Tx I need to get this right. Any help would be much appreciated.
Do not use PAG oil unless changing compressor and hoses, it will not mix with any remaining mineral oil.
Ester oil is for R12 to R134A conversions, you cannot get all the mineral oil out of your compressor evaporator or hoses.
Just drain the oil you can from the compressor and replace it with ester oil, do not overfill with oil or it can reduce the cooling effectiveness. Replace the receiver drier and fit a new orifice tube, I think white is the largest one. Fit the R134A adapters to your old R12 fittings evacuate the system and charge with 80% of normal R12 charge by weight only!!
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polo91 (07-28-2017)
07-27-2017, 10:29 AM
#23
Drifting
Thread Starter
Quick update
About eight years ago I posted if you have an R12 system to stay with it and I did. But R12 has become expensive, hard to come by, and just a pain to deal with. I used some R12 substitutes but they were not satisfactory. When my condenser was damaged the change was made to R134A. The evaporator was removed and flushed with acetone as was the used condenser. The compressor was drained and a new dryer and orifice tube installed. Eight oz. of Ester Oil was added. The job wasn't really that difficult but I did have the use of a lift. Buttoned it up, pulled a vacuum, and put in the R134A and am well pleased with the results. With an outside temp of 95 and high humidity the vent temp runs between 50 to 57 degrees which works fine for the small roadster interior. It seems to run 50 to 54 below 1500 rpm and 55 to 57 above 1500.
I do wonder if the factory R134A C4s have a different condenser and does it fit my car? Also my wife drives an 05 Cadillac XLR (basically a C5 Corvette} and those temps are about ten degrees cooler. I would like to achieve that in my 91. .
By the way the whole job cost less than $200 including the used condenser, Walmart R143A was $4.88 a can.
I do wonder if the factory R134A C4s have a different condenser and does it fit my car? Also my wife drives an 05 Cadillac XLR (basically a C5 Corvette} and those temps are about ten degrees cooler. I would like to achieve that in my 91. .
By the way the whole job cost less than $200 including the used condenser, Walmart R143A was $4.88 a can.
07-31-2017, 07:33 AM
#24
Race Director
