# Low Pressure AC port

**URL:** <https://community.cartalk.com/t/low-pressure-ac-port/52979>\
**Category:** Maintenance/Repairs\
**Created:** [August 4, 2010, 7:16pm UTC](https://community.cartalk.com/t/low-pressure-ac-port/52979 "2010-08-04T19:16:11Z")\
**Posts on this page:** 6\
**Page:** 1

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**Author:** ![johninba](https://avatars.discourse-cdn.com/v4/letter/j/ed655f/32.png) [@johninba](https://community.cartalk.com/u/johninba)\
**Post date:** [August 4, 2010, 7:16pm UTC](https://community.cartalk.com/t/low-pressure-ac-port/52979/1 "2010-08-04T19:16:11Z")

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I need to add refrigerant to the AC system in my '02 Suburban but I can’t find the LP port. Where the heck is it?

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**Author:** ![tardis](https://avatars.discourse-cdn.com/v4/letter/t/f0a364/32.png) [@tardis](https://community.cartalk.com/u/tardis)\
**Post date:** [August 4, 2010, 7:31pm UTC](https://community.cartalk.com/t/low-pressure-ac-port/52979/2 "2010-08-04T19:31:40Z")

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So, how could you possibly know that the system is low on refrigerant? You couldn’t have connected gauges to both the low and the high ports if you can’t find the low port.

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**Author:** ![johninba](https://avatars.discourse-cdn.com/v4/letter/j/ed655f/32.png) [@johninba](https://community.cartalk.com/u/johninba)\
**Post date:** [August 4, 2010, 7:39pm UTC](https://community.cartalk.com/t/low-pressure-ac-port/52979/3 "2010-08-04T19:39:23Z")

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I bought a can of refrigerant with a pressure gauge port that needs to be connected to the LP port. Will this not indicate whether I need refrigerant?

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**Author:** ![tardis](https://avatars.discourse-cdn.com/v4/letter/t/f0a364/32.png) [@tardis](https://community.cartalk.com/u/tardis)\
**Post date:** [August 4, 2010, 7:59pm UTC](https://community.cartalk.com/t/low-pressure-ac-port/52979/4 "2010-08-04T19:59:57Z")

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It’ll only give you a guess at it. If there is some other problem with the system, then your low pressure only reading can mislead you.

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**Author:** ![johninba](https://avatars.discourse-cdn.com/v4/letter/j/ed655f/32.png) [@johninba](https://community.cartalk.com/u/johninba)\
**Post date:** [August 4, 2010, 8:33pm UTC](https://community.cartalk.com/t/low-pressure-ac-port/52979/5 "2010-08-04T20:33:23Z")

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Thanks!

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**Author:** ![Joseph\_E\_Meehan](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/joseph_e_meehan/32/21_2.png) [@Joseph\_E\_Meehan](https://community.cartalk.com/u/Joseph_E_Meehan)\
**Post date:** [September 13, 2010, 9:37am UTC](https://community.cartalk.com/t/low-pressure-ac-port/52979/6 "2010-09-13T09:37:45Z")

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With modern A/Cs we generally recommend not making this a DIY fix. Far too many errors and some possibly dangerous are made by the DIYs While I did do some such work in the old days, I would not do it myself today, nor would I have anyone other than a properly equipped and knowledgeable professional do my work.