How long should you pull a vacuum on a car AC system?
With a vacuum pump connected to both, low and high air conditioning system sides pull a deep vacuum for at least 5-45 minutes. A vacuum of about 500 microns or 29.92 hg gauge pressure is needed for removing any moisture that may have entered the system along with the non-condensable gases while it was open.
How do I find a vacuum leak in my AC?
You can and should pull a vacuum, look at the reading on the manifold gauge set, let it sit for some amount of time (overnight is best), and see if the vacuum reading drops, because if it does, there’s a leak somewhere. But the vacuum itself is really almost no help in finding the leak.
How many microns should you pull a vacuum on AC system?
with a vacuum pump. Why a Vacuum Pump? ASHRAE recommends evacuation to below 1000 microns for moisture removal and below 500 microns after replacing a compressor. Some equipment manufacturers call for evacuation to 400 microns to ensure that harmful water vapor is removed from the system.
Can you pull a vacuum on just the low side?
Yes. You can pull a vacuum from one port. The AC system is a continuous loop. There is a part known as an orifice tube which restricts the flow of refrigerant, but doesn’t stop it.
Does pulling a vacuum remove refrigerant?
There’s absolutely no need to use a vacuum pump to remove the refrigerant. It’s really easy to remove the refrigerant by condensing it out. If you’re a shade tree mechanic, this is what has worked for me to recover and store R134a: Get a refrigerant recovery tank with 1/4″ fittings.
What happens if you don’t pull a vacuum on an AC system?
If you do not evacuate the system to remove air and moisture, you will reduce heat transfer capability through the refrigerant because air which is 78% nitrogen is not condensable in automobile systems. Moisture in an A/C only induces corrosion and more problems.
How do I know if my vacuum pump is leaking?
One of the most accurate methods of vacuum leak detection is the helium leak detector. A sensor is usually placed near the inlet to the vacuum pump to detect any increase in helium concentration in the air stream. Helium is then sprayed on any potential leak points in the system or piping.
When a leak is found in an automotive air conditioning system?
If the detector indicates a leak, the evaporator or the line connecons to the evaporator are leaking. After a system has been opened for repair, the system should be properly leak tested before charging with refrigerant. The system should hold a deep vacuum (27 in HG. or more) for at least one minute before charging.
How many microns is considered a deep vacuum?
Evacuation is complete when a system holds at 500 microns. A compound gauge only indicates a vacuum is being produced. A micron gauge is the only device that accurately reads the vacuum pressure needed for deep vacuum.
How many microns is a perfect vacuum?
In the micron vacuum scale, we start at 760,000 microns at sea-level atmospheric pressure and work down towards a perfect vacuum of 0 microns or 0″ Hg. That is why a lower number in the micron vacuum scale equals a better/deeper vacuum; a higher number equals a worse/less deep vacuum.
How long does it take to vacuum a car AC system?
First, pull the system down into a vacuum, shut off the valves on the gauges and shut the vacuum pump off. Check to see if you have less than 1″ of vacuum in 10 minutes. If you do, you have not wasted 1/2 hour vacuuming down the system, just to tear apart to fix a leak.
Where is the vacuum nozzle on a car AC?
It is positioned amid the orifice tube or the expansion valve and the condenser. When you follow the AC’s compressor linkages and to the bottom of the car, a nozzle would be visible. This very nozzle is the low side service port that is stuck amid the compressor and the evaporator. Now the real work to vacuum AC system can start.
What to do if you have a vacuum leak in your car?
If the reading goes hay wired, there is a potential leak. Contrarily, if everything is fine, you can detach the vacuum pump and place the hose in a refrigerant. Start your car, turn the AC on, and open the low pressure valve that is present on the gauge in a slow manner. This step is undertaken to ensure a constant flow of refrigerant into the AC.
When to evacuate an air conditioner with a vacuum?
When combined with refrigerant and lubrication, moisture will turn acidic (hydrochloric acid) and start to eat up the AC system components from the inside out. Aluminum components and seals are particularly vulnerable. To repeat, we recommend 30-45 minutes of evacuation at 28 – 30″ Hg of vacuum. Why 28-30″Hg of vacuum?