Replace A/C exp valve with orfice tube? (1 Viewer)

Jul 22, 2004
St Petersburg, Florida
Has anyone done away with their expansion valve and converted to orfice tube?


I'm on a quest to lower my AC vent temp and make it more reliable.
Best attainable temps at the vent is 58 deg when using R12 and 60 deg using R134. I have tried various refrigerants and very combination of pressures.
Heater valve not leaking or passing hot water inside. All vents operating and closing properly and operating in the recirculating position.
With 134A works best 40PSI on low, 225 PSI high.

After having the evaporator out four times since last summer, thinking about converting to orfice tube. First time replaced a frozen exp valve. Next time wanted to try a new 134 exp valve in the quest for colder temp, next time the desicant bag broke in the drier sending junk in the exp valve.

A month ago evaporator (less than a year old) cracked and leaked. Determined to have colder A/C, bought another new exp valve, new evaporator, new drier and replaced condenser with a new condenser. Found a condenser in the junkyard that was almost brand new in a Volv0 wagon of a more efficient design than the LC one. Complete new system. Filled with R134. Still only 60 deg at the vents. I could almost live with that and decided that's the best that can be achieved.

This week A/C blowing warm again. Appears exp valve stuck partially open. Low side pressure won't drop below 70 PSI.

So here I am thinking of a better way.

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