Purging air from A/C Manifold Gauge Set
05-03-2014, 02:17 PM
#1
Melting Slicks
Thread Starter
Purging air from A/C Manifold Gauge Set
What process do you guys follow to purge the air from an A/C Manifold Gauge Set when attaching it to check pressures and add refrigerant, if needed, so you don't introduce air into the system?
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05-03-2014, 03:05 PM
#2
Heel & Toe
Hi GCG,
I do it one of two ways.
1. connect up the can , or canister, to the gauge set, then puncture the can, open one vale and loosen the hose at the connector going to either the hi or low side and listen for the air to escape and give it a second or two. Tighten connection and repeat for the other line.
2. connect up the gauges , manifold etc as though you are going to fill the system. If there is some pressure showing on the gauges, slightly loosen the hose connections at the manifold for both sides. You could loosen the yellow fitting at the can and purge both sides this way. Make sure the can is not punctured if you do it this way.
Just look at the set up and you will see which way will work best for you. Most people will do it one of these ways or slightly modified. I know I left out a couple of obvious steps, but this will give you the general steps.
Good Luck.
I do it one of two ways.
1. connect up the can , or canister, to the gauge set, then puncture the can, open one vale and loosen the hose at the connector going to either the hi or low side and listen for the air to escape and give it a second or two. Tighten connection and repeat for the other line.
2. connect up the gauges , manifold etc as though you are going to fill the system. If there is some pressure showing on the gauges, slightly loosen the hose connections at the manifold for both sides. You could loosen the yellow fitting at the can and purge both sides this way. Make sure the can is not punctured if you do it this way.
Just look at the set up and you will see which way will work best for you. Most people will do it one of these ways or slightly modified. I know I left out a couple of obvious steps, but this will give you the general steps.
Good Luck.
05-03-2014, 06:32 PM
#3
Burning Brakes
Depends if you're on a system with pressure or not. If the system has pressure, hook up the hoses, manifold valves closed, loosen the hoses at the manifold a little till you smell refrigerant. Hook up the can puncture the can and loosen the hose at the manifold till you again smell refrigerant. Start engine, turn can bottom up and open the low side valve. Should have someone hold the throttle to 1500 rpm or so while charging. Charge till you have 37 to 40 degrees on the 134 scale.
System in a vacuum, you've pulled a vacuum. the hoses should have a vacuum on them except the charging hose, if you closed the valves before you shut off the pump. The only hose you need to bleed is the charging hose same as above.
If the system has no standing pressure you need it pulled in a vacuum before charging, it has air in it. If you charge a system with air in it, air, refrigerant and oil = acid. It will eventually eat the aluminum from the inside, and you will have a mess.
I know,, a lot of guys says they just charge um up, but that's not the right way. Depends on how much moisture is in the system, if it works or not. If the system has moisture, it WILL freeze and it could plug up the orfice tube. That causes high head pressure and could burn the belt off or ruin the compressor. GOOD LUCK
System in a vacuum, you've pulled a vacuum. the hoses should have a vacuum on them except the charging hose, if you closed the valves before you shut off the pump. The only hose you need to bleed is the charging hose same as above.
If the system has no standing pressure you need it pulled in a vacuum before charging, it has air in it. If you charge a system with air in it, air, refrigerant and oil = acid. It will eventually eat the aluminum from the inside, and you will have a mess.
I know,, a lot of guys says they just charge um up, but that's not the right way. Depends on how much moisture is in the system, if it works or not. If the system has moisture, it WILL freeze and it could plug up the orfice tube. That causes high head pressure and could burn the belt off or ruin the compressor. GOOD LUCK