# Location for A/C Orfice Tube

**URL:** <https://community.cartalk.com/t/location-for-a-c-orfice-tube/2229>\
**Category:** Maintenance/Repairs\
**Created:** [July 26, 2007, 6:25am UTC](https://community.cartalk.com/t/location-for-a-c-orfice-tube/2229 "2007-07-26T06:25:46Z")\
**Posts on this page:** 20\
**Page:** 1

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**Author:** ![Skypilot](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/skypilot/32/237_2.png) [@Skypilot](https://community.cartalk.com/u/Skypilot)\
**Post date:** [July 26, 2007, 6:25am UTC](https://community.cartalk.com/t/location-for-a-c-orfice-tube/2229/1 "2007-07-26T06:25:46Z")

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Working on replacing the A/C Compressor on a 2000 Chevy S-10 Extreme with the 2.2 liter 4 cylinder engine and auto transmission. Want to change out the Orfice Tube. So far I have not been able to locate it. Any help would be greatly appreciated!

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**Author:** ![Big\_Riviera\_1990](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/big_riviera_1990/32/43_2.png) [@Big\_Riviera\_1990](https://community.cartalk.com/u/Big_Riviera_1990)\
**Post date:** [July 26, 2007, 6:44am UTC](https://community.cartalk.com/t/location-for-a-c-orfice-tube/2229/2 "2007-07-26T06:44:36Z")

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You’ll find it in the liquid line leading from the condenser to the evaporator core. Trace the line from the condenser to the firewall. You should find a fitting at the firewall connecting the line to the evaporator inlet. Depending on how this vehicle was equipped, you may find a section of tubing of smaller diameter that is in the line between the evaporator and the condenser. The orifice tube will be in that thin section of tubing. If this section of tubing is not present in your A/C system, then the orifice tube is in the line before the evaporator inlet, or in the inlet itself.

-Matt

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**Author:** ![Skypilot](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/skypilot/32/237_2.png) [@Skypilot](https://community.cartalk.com/u/Skypilot)\
**Post date:** [July 26, 2007, 7:57am UTC](https://community.cartalk.com/t/location-for-a-c-orfice-tube/2229/3 "2007-07-26T07:57:02Z")

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Thanks for answering my question! I will check it out this afternoon. Again Thanks!

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**Author:** ![Tester](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/tester/32/15976_2.png) [@Tester](https://community.cartalk.com/u/Tester)\
**Post date:** [July 26, 2007, 12:11pm UTC](https://community.cartalk.com/t/location-for-a-c-orfice-tube/2229/4 "2007-07-26T12:11:12Z")

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[b]On GM vehicles, the orifice tube is located in the high pressure line between the condensor and evaporator. But not always at the evaporator end of the line. Sometimes their located at the condensor end of the high pressure line.

Tester[/b]

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**Author:** ![willey](https://avatars.discourse-cdn.com/v4/letter/w/a9adbd/32.png) [@willey](https://community.cartalk.com/u/willey)\
**Post date:** [July 26, 2007, 2:58pm UTC](https://community.cartalk.com/t/location-for-a-c-orfice-tube/2229/5 "2007-07-26T14:58:19Z")

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Again STAR your reply is wrong is so many ways.

GM hasn’t used a TXV system in years. This system uses a fixed orifice tube.

There isn’t a single tech out there that would upgrade the system to a TXV. The system is made to operate at it’s maximum efficency using a fixed orifice tube and to suggest that it can be upgraded is downright stupid.

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**Author:** ![system](https://global.discourse-cdn.com/cartalk/original/3X/1/d/1d47c66a543aa6c5a7873bb2320858f978ff52ed.png) [@system](https://community.cartalk.com/u/system)\
**Post date:** [July 26, 2007, 4:22pm UTC](https://community.cartalk.com/t/location-for-a-c-orfice-tube/2229/6 "2007-07-26T16:22:42Z")

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My OT is located at the evaporator, 99 Sonoma 2.2.  
My 04 Malibu has a TXV.

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**Author:** ![ok4450](https://avatars.discourse-cdn.com/v4/letter/o/e9bcb4/32.png) [@ok4450](https://community.cartalk.com/u/ok4450)\
**Post date:** [July 26, 2007, 4:52pm UTC](https://community.cartalk.com/t/location-for-a-c-orfice-tube/2229/7 "2007-07-26T16:52:45Z")

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I was not aware that GM has used a TXV in what? 25 years?  
Are you talking about a TXV or an XV?

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**Author:** ![Skypilot](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/skypilot/32/237_2.png) [@Skypilot](https://community.cartalk.com/u/Skypilot)\
**Post date:** [July 26, 2007, 10:55pm UTC](https://community.cartalk.com/t/location-for-a-c-orfice-tube/2229/8 "2007-07-26T22:55:59Z")

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I noticed that the website you posted was for residential HVAC. I’m not working on my house A/C unit. Thanks anyways!

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**Author:** ![system](https://global.discourse-cdn.com/cartalk/original/3X/1/d/1d47c66a543aa6c5a7873bb2320858f978ff52ed.png) [@system](https://community.cartalk.com/u/system)\
**Post date:** [July 27, 2007, 2:54pm UTC](https://community.cartalk.com/t/location-for-a-c-orfice-tube/2229/9 "2007-07-27T14:54:18Z")

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It is a TXV, they started using them again because the systems are so small. Mine only holds 1.2 lbs, my 99 Sonoma 1.75 lbs with just a std cab.  
The OT is cheap but will not give cooling under all conditions.  
The car is a 04 Malibu LS 3.5 L, here’s a sentence out of the SI.

Replace the thermal expansion valve. Refer to Thermal Expansion Valve replace.

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**Author:** ![system](https://global.discourse-cdn.com/cartalk/original/3X/1/d/1d47c66a543aa6c5a7873bb2320858f978ff52ed.png) [@system](https://community.cartalk.com/u/system)\
**Post date:** [July 27, 2007, 4:03pm UTC](https://community.cartalk.com/t/location-for-a-c-orfice-tube/2229/10 "2007-07-27T16:03:09Z")

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This is the first time I have seen it referred as a TEV, I don’t think the old timers will change to TEV.

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**Author:** ![willey](https://avatars.discourse-cdn.com/v4/letter/w/a9adbd/32.png) [@willey](https://community.cartalk.com/u/willey)\
**Post date:** [July 27, 2007, 5:12pm UTC](https://community.cartalk.com/t/location-for-a-c-orfice-tube/2229/11 "2007-07-27T17:12:04Z")

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Once again STAR we are talking about a automotive application. If you would read the link yourself you would see it is a commerial application expansion valve. There is no mention of this valve in a automotive application.

False and misleading information again. Here comes my flag of this post.

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**Author:** ![ok4450](https://avatars.discourse-cdn.com/v4/letter/o/e9bcb4/32.png) [@ok4450](https://community.cartalk.com/u/ok4450)\
**Post date:** [July 27, 2007, 6:11pm UTC](https://community.cartalk.com/t/location-for-a-c-orfice-tube/2229/12 "2007-07-27T18:11:11Z")

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I have to respectfully disagree that A/C system size has anything to do with whether it uses an orifice tube or expansion valve.  
My son has a 96 Camaro that has an orifice tube, and the total system charge on that car is LESS than one pound. As also stated by the fender tag.

I also have to disagree that an orifice tube is somehow inferior. My opinion is that they’re great; nothing to screw up uness an orifice screen gets clogged and if that happens then the orifice tube is the least of the worrries.  
There’s been no inferior cooling problems caused by an orifice tube that I’m aware of.

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**Author:** ![willey](https://avatars.discourse-cdn.com/v4/letter/w/a9adbd/32.png) [@willey](https://community.cartalk.com/u/willey)\
**Post date:** [July 27, 2007, 7:11pm UTC](https://community.cartalk.com/t/location-for-a-c-orfice-tube/2229/13 "2007-07-27T19:11:52Z")

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I agree with OK4450. The orifice tube has been used for decades. It is simple and efficient for automotive applications.

If expansion valves were so good why did the do away with the POA,STV,STV/BPO,EPR,VIR,ETR expansion valves?

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**Author:** ![willey](https://avatars.discourse-cdn.com/v4/letter/w/a9adbd/32.png) [@willey](https://community.cartalk.com/u/willey)\
**Post date:** [July 27, 2007, 7:15pm UTC](https://community.cartalk.com/t/location-for-a-c-orfice-tube/2229/14 "2007-07-27T19:15:51Z")

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STAR… you are talking about commerial,stationary and industrial units. This valve is not used in a automotive application as noted in your previous link(which I flagged and was then removed from this discussion).

Again I will ask you if you even bothered to read the link you posted. The valve is not used in automotive A/C applications.

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**Author:** ![system](https://global.discourse-cdn.com/cartalk/original/3X/1/d/1d47c66a543aa6c5a7873bb2320858f978ff52ed.png) [@system](https://community.cartalk.com/u/system)\
**Post date:** [July 27, 2007, 8:05pm UTC](https://community.cartalk.com/t/location-for-a-c-orfice-tube/2229/15 "2007-07-27T20:05:16Z")

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I guess then GM likes to waste money, but they really can’t spare any.

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**Author:** ![willey](https://avatars.discourse-cdn.com/v4/letter/w/a9adbd/32.png) [@willey](https://community.cartalk.com/u/willey)\
**Post date:** [July 27, 2007, 8:21pm UTC](https://community.cartalk.com/t/location-for-a-c-orfice-tube/2229/16 "2007-07-27T20:21:38Z")

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I agree with OK4450. The orifice tube has been used for decades. It is simple and efficient for automotive applications.

If expansion valves were so good why did the do away with the POA,STV,STV/BPO,EPR,VIR,ETR expansion valves?

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**Author:** ![ok4450](https://avatars.discourse-cdn.com/v4/letter/o/e9bcb4/32.png) [@ok4450](https://community.cartalk.com/u/ok4450)\
**Post date:** [July 28, 2007, 5:21am UTC](https://community.cartalk.com/t/location-for-a-c-orfice-tube/2229/17 "2007-07-28T05:21:42Z")

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The “orifice tube” system is good enough that I’ve actually gone and made some my own for a couple of custom systems involving R134 conversions.

I did this due to a few quirky pressure problems that were not quite as I wanted them to be and rather than dink around with various orifice tubes, I simply made my own.  
Machined them out of brass on my lathe and I can’t say enough good about how well they worked.  
On both cars, the pressures were controlled perfectly and the A/C would put out 30 degree air on a 100 degree Oklahoma summer day.  
When you get a 70 degree drop over the ambient temperature then things are going right.

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<div class="post-metadata">

**Author:** ![Skypilot](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/skypilot/32/237_2.png) [@Skypilot](https://community.cartalk.com/u/Skypilot)\
**Post date:** [July 28, 2007, 8:15am UTC](https://community.cartalk.com/t/location-for-a-c-orfice-tube/2229/18 "2007-07-28T08:15:04Z")

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Thanks for everones input. I found the orffice in the High pressureor or Liquid line in the Evaporator. Again thanks!

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**Author:** ![Big\_Riviera\_1990](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/big_riviera_1990/32/43_2.png) [@Big\_Riviera\_1990](https://community.cartalk.com/u/Big_Riviera_1990)\
**Post date:** [July 28, 2007, 6:00pm UTC](https://community.cartalk.com/t/location-for-a-c-orfice-tube/2229/19 "2007-07-28T18:00:59Z")

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Holy jeebus!  
How much to make me onea those and ship it down to Florida?

Oh and while I’m in the thread I thought I’d ask.  
What do all think about automatically self-adjusting orifice tubes? I’ve got an OEM tube in the system with a clogged screen and I’m thinking about going in to replace it. The OEM replacement is $3 and the adjusting tube is $25. One thing that’d make it worth it for me is a reduction or elimination of compressor cycling because this compressor makes its presence known when it cycles. 30?F air would be nice too!! =D

-Matt

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**Author:** ![system](https://global.discourse-cdn.com/cartalk/original/3X/1/d/1d47c66a543aa6c5a7873bb2320858f978ff52ed.png) [@system](https://community.cartalk.com/u/system)\
**Post date:** [July 28, 2007, 7:32pm UTC](https://community.cartalk.com/t/location-for-a-c-orfice-tube/2229/20 "2007-07-28T19:32:53Z")

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Waste of money for VOT, if the one in there plugged you need more than a new OT.  
Most likely you need a new compressor if it is metal.  
If it had sealer put in a complete flush and new condenser, if parallel. Good Luck
