I am retrofiting my system on 89 f-150 to 134a. ANyhow, I am using a refriderator compressor for vacuum pump.
I need to check to see if it is holding vacuum. Do I leave the guages open or close them?
How to use ac guages
Apr 26, 2004
2 Replies
Holding vacuum test not the best way to test system. Rubber pipes will not allow air in under vacuum but will leak under pressure. Use Oxygen free nitrogen to 150psi and hold for 30 mins. leave high pressure guage open.
If you want to use vacuum test leave low pressure open and look for a vacuum of 60.
best of all use a R12 replacement refrigerant and leave system intact.
Holding vacuum test not the best way to test system. Rubber pipes will not allow air in under vacuum but will leak under pressure. Use Oxygen free nitrogen to 150psi and hold for 30 mins. leave high pressure guage open.
If you want to use vacuum test leave low pressure open and look for a vacuum of 60.
best of all use a R12 replacement refrigerant and leave system intact.
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