Freon - add to high or low side?

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Jul 10, 2006 | 09:12 AM

robertbartsch

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From: Hartsdale, NY

Freon - add to high or low side?

I have a set of guages but have not done this in a while. Do you add freon to the high (red) side or low (blue) side?

Thanks...

Jul 10, 2006 | 09:22 AM

Weezzer

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From: South Alabama

Low side.

Jul 10, 2006 | 09:34 AM

robertbartsch

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From: Hartsdale, NY

good - thanks.

When the sytem is running, what are the typical pressure readings for the high and low side? Is there any idication of how much freon should be added from the pressures?

System is newer 1996 (Freon is R-10, A-10???)? I thought these systems typically hold less freon - 2.5 of the small cans when empty - right. Car is BMW Series 7.

My system is NOT open but is not running real cold - I think I just need a tad - 1/2 can maybe.

Thanks...

Jul 10, 2006 | 10:48 AM

A-Dub

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From: Houston, TX

Pressure readings are dependent on air and humidity readings, I would imagine they also depend on the model of car. I would guess low side in the 30-45 range, high side 150-250 range

Jul 10, 2006 | 11:02 AM

1badragtop

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From: Scottsdale, AZ

All automotive should be R-134a after 1994. A/C could be waek due to any number of reasons including, but not limited to low on charge. I would first clean condensor and check pressures. Low should be around 30psi and high should be around 200. Too much refrigerent could make the problem worse as it would create too much psi and the switch would kick off a/c. The best thing to do if you isolate your concern to a refrigerant level concern is to evacuate completey and charge to level posted on shround.

Jul 10, 2006 | 12:31 PM

robertbartsch

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From: Hartsdale, NY

Thanks.

I bought a vacume pump several years ago but don't have a way to recover any old freon - so I'd rather not open the system. It is cold but not real cold.

I'll blow out the condensor and check teh presures witht he guages, I suppose.

Jul 10, 2006 | 09:40 PM

Cld069

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From: Greenwood

add to the high side when the ac is off and add to the low side when the ac is on. i think thats the way it goes. i havnt rechared in a while so someone correct me if i am wrong.