Ac orifice tube replacement

Hello all, so my current problem. I think the orifice tube needs to be replaced ( tell me other wise)
The ac goes from cold to warm to cold.

The pressure reads 36 Lo 250 high when it is 85 outside and standard idle.

It reads 19/350 when it is at 2k rpm also at 85 outside

The steps would be

  1. remove the R134a (take it to a shop or get proper tools)
  2. replace orifice tube
  3. recharge the system (this would require a vacuum , R134a, oil for the system…right?)

What year?


2014 Subaru Impreza hatchback sport limited

I think I misspoke above. It would be the expansion valve

What are the pressures just before the A/C begins to blow warm? The compressor will be disabled if the pressure reaches 425-450 PSI.

I wonder if the system is over charged, you are seeing 350 psi with an ambient temp of only 85 degrees? That is the pressure I see on a 110 degree day.

I agree that 350psi is too high for 2000rpm at 85 degrees ambient temp. Are both cooling fans running at that time?

Yeah both cooking fans are running. So thinking could be overcharged? It seems to do the cold warm cold on our hotter days ie 95-100+

I’d let an A/C pro diagnose the situation. If you still want to do your own work… use the diagnosis given to you by the A/C shop.

I’m sure you are aware of the specialized tools needed for such an endeavor. Most people do not have these tools.

Yeah I think I’m in agreement and at the point of taking it to the shop. It was enjoyable to at least learn a few things in my research. Thanks for the help and guidance. Much appreciated!

The expansion valve is malfunctioning.


Does it make sense to have the auto shop remove the R134a… I do the repair then go back for a refill (vacuum etc)?

If you don’t have the proper equipment to recover the refrigerant?



It’s illegal to knowingly vent refrigerant into the atmosphere. If you don’t have a Robinair (or other) refrigerant recovery equipment, go to a shop.

As for your problem (low low-side and high high-side pressures), it points to an expansion valve.
I had a similar problem in an older Toyota (I was actually showing a vacuum on the low side)
Also, it goes without saying to replace the receiver/drier or accumulator anytime you open up the system.

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Took the car in yesterday to have it inspected. They believe air was in the system so they did an evac and replace the Freon. Seems to be blowing freezing air. Shall see and hope it holds up