# Pumping and charging AC system



## H. Phillips (Jan 5, 2010)

Freon leaked out of the suction Schroeder (SP?) valve so I plan to pump out and recharge it. With a new valve of course. I see some instructions say to pump down to 27 in HG and nothing said about oil. Others say to pump down to 29 in HG and to add oil. Does the oil boil out between 29 and 27 HG?


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## cowboy dan (Apr 11, 2010)

H. Phillips said:


> Freon leaked out of the suction Schroeder (SP?) valve so I plan to pump out and recharge it. With a new valve of course. I see some instructions say to pump down to 27 in HG and nothing said about oil. Others say to pump down to 29 in HG and to add oil. Does the oil boil out between 29 and 27 HG?


 
ac repairs are what i would call a shop only job. for alot of reasons


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## 47_47 (Sep 11, 2007)

cowboy dan said:


> ac repairs are what i would call a shop only job. for alot of reasons


I agree with the above. The only time you really need to add oil is if you are replacing a major component or had a catastrophic leak. Pump it down to 27-29" after two minutes turn pump off, wait ten and check to make sure the vacuum holds. Pump down for another 30. Recharge with weighed amount of refrigerant on low side with liquid.

Make, model and year would be helpful. Schraeder valves rarely leak, check your evap.


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