I'm wanting to charge the air in my truck. I have the manifold gauges and a 30lb. cylinder of 134a. what I can't remember is where the low and high side pressures should be on these gauges. i'm thinking high side 150-200 and low side 30-40 is this correct. haven't had to charge one in awhile

I'm wanting to charge the air in my truck. I have the manifold gauges and a 30lb. cylinder of 134a. what I can't remember is where the low and high side pressures should be on these gauges. i'm thinking high side 150-200 and low side 30-40 is this correct. haven't had to charge one in awhile

Use a scale and charge the quantity listed on the MFG label affixed under the hood. Ususlly around 2lbs. The low pressure side will generally read around 35 - 55 psi when fully charged and under load. The high side will be anywhere below 250 psi. Remember all pressures vary dramatically dependant on ambient conditions and system loading.

Use a scale and charge the quantity listed on the MFG label affixed under the hood. Ususlly around 2lbs. The low pressure side will generally read around 35 - 55 psi when fully charged and under load. The high side will be anywhere below 250 psi. Remember all pressures vary dramatically dependant on ambient conditions and system loading.



he is absolutely right, AC pressure is based on ambient temperatures, and there is no set pressures for charging any AC unit, on cars or home. depending on how warm or cold it is on that day, will reflect on your charging pressures.