How to Recharge a Car's A/C System Using a Manifold Gauge Set & Vacuum Pump - Air Conditioning

How to completely refill a vehicle air conditioning system from empty using a Manifold Gauge set and vacuum pump. Do it yourself and save $100's

[caymanwest]

Always appreciate YouTubers that share their knowledge and skill. It was also refreshing to see that you corrected yourself in the comment section that vacuuming an a/c system does not remove oil. Just want to make three points for newbies that may attempt this:

1. When connecting & disconnecting both quick connect couplers to the Low & High side ports, they should be in the Closed (counterclock wise position) meaning the needle is in the retracted position. Then make sure your gauges are in the closed position. And then Open the quick connect couplers by turning them clockwise to depress the needle.

2. Your system had no refrigerant to begin with. That indicates that you like replaced a component such as the compressor before starting this procedure. In that case, vacuuming the system is the logical next step. However for most others who are simply attempting to add refrigerant to a system that is low on refrigerant, you will not be vacuuming the system UNLESS you have evacuated the system first. This is the preferred method but requires an evacuation procedure and likely a service station to perform that function (likely at $0 to minimal cost since they benefit from the recaptured refrigerant).

3. You should not need to re-bleed your yellow line between can-change charges if you temporarily close the valves at the can and manifold during the changeover before resuming the process.

Thanks for the video!

[willfoster]

pag oil does not evaporate under vaccum - only when exposed to air (positive pressure) most cars have 7 ounces total in the system. the 2oz cans should be added from time to time and its a really easy and cheap way to do it. DO NOT ADD 7 ounces when charging a system. Even if you buy and replace the compressor DO NOT ADD A FULL 7 ounces. The compressor will come with 3 ounces already - you do not want to overfill the system with PAG oil.

[ParabellumX]

[*This is to viewers who may attempt to connect a manifold gauge set to a system and try to charge it.]
Although he is initially pulling a vacuum, essentially removing any/all non-condensables from the system, the proper way to perform the initial steps would have been to first turn the vacuum pump on before back-seating (opening) the valves on the gauges. Other non-condensables (and possibly other refrigerant types from previous use) most likely exist inside of the hoses, and could travel into the system. It's always good practice to get into that habit in case you ever forget to purge your hoses one day.
Also, you never want to pull a vacuum on a system that has a leak. [If your A/C system doesn't have any refrigerant in it, or is otherwise low according to its factory sticker or nameplate, IT HAS A LEAK. These systems are closed systems (meaning the refrigerant never gets 'used up' or is depleted from a system. It should still maintain its factory charge, whatever amount was weighed in after it was manufactured.)] The first step on a system that is suspected of having a leak is to first find that leak using an electronic leak detector in conjunction with a soap bubble solution. If the system is completely empty, pressurize it to the system's minimal, allowable low-side pressure with nitrogen, with a trace amount of the refrigerant that belongs in that system.
A side note: A digital manifold gauge set (such as the Fieldpiece SMAN) works great, and is very accurate when monitoring your inches of mercury (i.e., your vacuum pressures). It facilitates decay tests, vacuum pressure tests, etc.
You need to test your hoses individually, to verify they aren't leaking at their fittings through the O-rings, etc. Otherwise, you may be chasing a leak in a system that doesn't exist.
When using an analog gauge set while pulling a vacuum, its impossible to know where your vacuum is at during the decay test; you can't see with accuracy how far down into a vacuum you are pulling the system. Am analog gauge set doesn't display microns - the crucial measurement used to help facilitate pulling a refrigeration system down into a deep vacuum. [The EPA (Environmental Protection Agency) recommends that we are to pull a minimal, single, deep vacuum of 500 microns, or a triple-vacuum of 1000 microns.] This is where a digital manifold or a micron gauge comes in handy.
If, during the decay test, the system creeps up past 1000 microns withing a 20-minute span, there is still a leak in the system, and will need to be addressed before continuing.

[cruzsanchez]

Always turn the valves off before installing them on to the vehicle's ports. If you install them fully open two things can happen.
First if the valve is open you can damage the vehicle's port (needle)
Second refrigerant can escape and may cause air to enter the system

[thevendetta]

Love the detail on this video. You went step by step in explaining everything instead of assuming someones knowledge and skipping over what would be "common knowledge"

[victormendoza]

I’m a new in your channel and for sure you are a good teacher explaining step by step how to complete a a/c charge, thank you very much you video is very helpful

[inmandon]

Dude 🎉 this guy for the win- saved me so much money- very good job explaining everything

[mohh]

Very good video in detail, thank you for helping others how to fix the ac

[OakHollowGarage]

The best video on this I've found. Simply an excellent explanation. Thanks for sharing.

[russelltownsend]

Glad I stumbled onto your video. I have watched another mechanic (he's a lot more animated) for years and he's really good too. I will come back to you often as my ancient vehicles (4 from 2014) need help. Well done and thanks. I subscribed today

[wiley]

2 Years late : NO OIL TO BE ADDED : Vacuuming a system does NOT remove oil. Oil is only added to a new compressor (if) it does not come pre oiled!

[packrat]

Great Video! I actually bought the same pump and guage setup and watched to refresh my brain before vacuuming. Good thing as I forgot to open the red/high side. doh!

I hit a deer at 70mph and totalled my truck. I rebuilt it including AC condenser and dryer. Final touches. Driving home tonight at dark it was blowing 39F out of the vent. I had to turn it off.
I credit using a scale that measures grams and put in just about exactly the factory stated 875 grams for my old Dodge. It's COLD! Awesome!

[Mrdubomb]

Good rule of thumb is high side should be twice ambient air temp in degrees F. Wondering, could you use engine vacuum to suck the system down if you didnt have a vacuum pump?

[hirdeyedecalcified]

Splendid video Ole Chap. A most brilliant, simple, yet thorough explanation of the Do's and Dont's. I am naming my next offspring after you my good man. Cherio!

[jcwguy]

Dont ever pull your refrigerant from the high pressure side. And dont ever recharge to the high pressure side. Thats is a VAPOR line. You're wanting to pull LIQUID ONLY! The low pressure hookup is a liquid line. Please be e609 certified before servicing AC systems.

[skytech_]

Tremendous help thank you for the video. Unfortunately my chevy has 1234yf. I'll have to buy those fittings since 1234a fitting doesn't work

[poleongriffis]

Your presentation on your tutorial was awesome 👍💯

[theoldguy]

Good video Im going to do mine kust got the stuff to, does the oil come in the freon or is it seperate?suggestion, try not to shake the can makes it hard to read.

[cyrusheshmati]

Very informative unlike most videos on u tube. THX

[Aliaksandr]

Wow ! You have zero dislikes - that's a great explanation and all I need to know to do the job myself, thank you ....🙂