Variable orifice tube vs fixed.

[95 Tahoe]

I will be pulling down the AC system sometime in the near future due to a leak. The AC has never been what I consider great in this truck in 100 degree weather with 100% humidity. Highway speeds vent temps will hover about 48 and in traffic climb to 60. One downside is the serpentine condenser which I don't plan to change due to its fairly new.

Currently the system has a fixed OE orifice tube in it that is .072". I am thinking about going with the variable orifice tube. Does it help or would the smaller orifice tube such as .062 or .067 be a better choice.

 

[Hipster]

You didn't state whether the system has ever been been properly vacuumed/recovered, new receiver/drier etc. You can't half do it and expect cooling performance. Expand a little bit on what was/was not done?

 

[95 Tahoe]

You didn't state whether the system has ever been been properly vacuumed/recovered, new receiver/drier etc. You can't half do it and expect cooling performance. Expand a little bit on what was/was not done?

It has. All components were replaced a few years ago. New dryer, evap core, condenser, orifice tube, and various hose. R4 compressor was resealed. It was vacuumed down and refilled with approximately 34-36 oz of 134a if memory serves. Airflow across the condenser is fine.

 

[L31MaxExpress]

I doubt you are at 100F and 100% humidity although I know humidity in the south can be killer. The more humidity the worse your vent temps will be.

I would look into a SD7H15 Sanden conversion while you have the system apart. The R4s never were a great compressor.

That being said I am seeing great results with the variable in the 97 Van.

 

[L31MaxExpress]

Where my vent temps normally run in the 97 van now. It has a drop in replacement micro tube parallel flow condenser. Driver side center vent.

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[GM Guy]

curious as well, I have a ton of 95s, one of which is a crew cab. the regular cab will freeze you out but the crew cab needs all the help it can get. lol