It’s been 4 years since the video so I am sure you have figured it out but there is a way to avoid losing refrigerant when disconnecting the can. Close the can valve first. The compressor will pump out the yellow line. Then close the low pressure valve.

Excellent!!! I watched tons of vids on this being a newbie never done a/c on my truck. You filled the gaps of what the others do not include. Such as 1. how the manifold valve knobs control the flow 2. leaks 3. new can adapter. Thank you!

I had the manifold setup to replace a condenser two years ago. The steps to top off a system are very different than pulling a vacuum first on a complete system evacuation. This is the only video I could find that explains ‘manifold functionality’ clearly. I went out and topped off my Accord in about 15 minutes. I actually purged the all three hoses with the Freon can attached to the yellow delivery line before hookups to the system. After closing the Freon can valve and both manifold valves I attached the manifold system to get readings. Then opened the Freon valve before opening blue low side periodically and bumped the High side to about 250. Closed the can off and held it above the manifold using gravity to help drain the the yellow charging line...... Like 👍 a Boss. Really, again, you did a great job taking all the mystery out of the manifold functionality.

Mistakes or not, I appreciate your careful explanation of the steps to take. Took care of my truck today following your lead. Thanks very much!

Thanks 50's kid. I see that I need a lot more tools. Explaining the laws on how to and how not to dispose of refrigerant saved me a fat ticket or a one way trip on the grey goose shackled from head to toe. You took no shortcuts and you cut all the none informative mumbo jumbo which leads me to believe that you did it primarily as an informative video and not to become a contestant on dancing with stars. Good job. I got to go to the hardware store before I single handedly fry all of the world's electrical components or faces. You da man. I'm subscribing.

Man! I'm watching hundreds of videos on AC repair and this is the best one! I ordered the same manifold gauge so it was helpful to see it in action, also I want to add uv dye. Thank you so much!

The most comprehensive video for DIYers. Fantastic job. Thank you for sharing it with us.

Very good presentation! You explained the reasons how, why n when the steps are preformed. I find that most You tube Videos' do not cover topics as well as you did. GREAT JOB! I forwarded this to my son so he can see what I was telling him as to how to fis his cars AC. From a retired Aircraft, auto, RV mechanic and instructor.

Great video that many mechanics probably don't want many to see. Only thing is that once you open the system by removing the Schrader valves, run the vacuum pump on it for at least 30 min.

You probably already know this by now. The valve you screwed on the can adapter should be a back seat in front seat valve meaning if you screw the valve all the way in to seat it is shut off or if you screw the valve all the way out to seat it is shut off.And refrigerant only flows when you're in the Midway point. If your valve does not work that way get yourself a front seat back seat valve that way you can backseat the valve and change the can without losing refrigerant from your line also not introducing air into your line. Very good video though you did a nice job of explaining it as well as including an ambient pressure chart.

Excellent video, and as you point out near the end, an R135-specific gas temperature/pressure chart will allow people to take into account the ambient temperature. In fact, if you connect the gauges and read the pressures BEFORE starting the car in the morning, both high and low pressures will be nearly equal (they will have equalized over night) and will reflect the outside morning air temperature. If the pressures are not close to one another it likely means there is an obstruction or defective component in the system. This is valuable information in and of itself and trivial to obtain. I have to say that I’m surprised at how few videos even mention using the gas temp/pressure chart as it’s very easy to use and highly informative. Thanks again!

sure wish I had seen this video before! Must have watched 50+ videos over a week or so, NONE mentioned the adapter you need for cans if you have an older gauge system. and few mentioned to only open the right (high pressure) for vacuuming only. Other easy to understand instructions, the chart for pressure at the end, etc. Many thanks!

totally appriciate you taking the time to make this video brother.

Awesome job ! Finally gettbe picture of the system. I have spent over a tbousand dollars and after 2 months, no ac again, now the compressor has seized . Nothing intbe repairs was replaced, but the guy said the pressure was very very high, but only just now found out about the expansion / TXV valve, which was probably what was wrong in the beginning, now the whole system is compromised. On a small SS income, Argh, this hurts. Its a 99 Ford Expedition , otherwise very sound condition. Thank you again.

You are my man, i'm happy to see someone knows what's going on behind the seen ( on those manifold gauges ) ... most of my friends believe that the 2 valves controls the high and the low lines .. and they call themselves professionals :D, tried many times explaining to them that the valves are used to control the connection between the low - high & the yellow .. but they don't seem to get it .

Very good video. I appreciate the energy and detail. Respectfully said (though) I realize that you can SLOWLY sort of shake the can (as you did) but most all sources say to avoid (if at all possible) doing that as it may allow liquid to hurt the compressor (when can is upside down). Doing so will fill the system faster, but increases potential of harming it. Just some general info & food for thought.

I would pressurize the blue line prior to hooking up the low side valve. Other than that, I didn't catch anything out of step. Awesome youtube channel, I appreciate you sharing.

I pulled vacuum on car last night and was going to check in the morning to see if it lost any pressure. I then thought to close the valves to check if manifold gauge would hold pressure. This morning, gauge at 25 instead of 30. Opened valves, system was still at 30. Glad I checked this way.

Very helpful. Most comprehensive video on these issues I've seen.

Best video I have come across, you hit all the points the other videos were missing thank you

Good tutorial to brush up on my skills. Thanks for sharing!

This was the best video on charging and helped me!! I had questions about vacuum with oil in the systems, and bleeding air and this video answered all of them. Very informative and easy to follow and listen to. Thanks!

My 01 sport trac a/c is finally needing some attention. I'm getting my parts list together right now. I'll let you know what happens soon. Thanks for sharing.

This is by far the best video I have seen regarding recharging an AC unit thank you very much you could not have done any better

If you vacuum your system down it is completely empty you can install the refrigerant as follows. This method is quicker and more efficient. First of all you do this procedure with your engine off you do not run the engine or the AC! After hooking up the can of refrigerant and purging the line you then invert the can and submerge it in a bucket of the hottest water you can get from your tap. This will not allow any water to go into your lines because they are perfectly sealed and under pressure. Swirl the can inverted in the hot water for 30 seconds to build pressure in the can. The next step with the engine off is to open the red line and within three seconds 12 ounces of refrigerant will shoot through the high side through the condenser to the receiver dryer the way the system was intended. Next close your red high-pressure line, your empty refrigerant can valve and remove and discard the empty refrigerant can. Repeat the same steps for the all other needed cans. For the last can, in this instance, open and close the high side valve intermittently if you’re not going to use the full 12 ounces. Each time you open and close the valve, weigh the remaining refrigerant on a small scale that way you’ll be able to know how much to go. The final step is to close both valves on the manifold gauges and then start the engine. Run the AC on high with a temperature gauge in the center register with the fan on high and the windows and doors closed and your air recirculating not taking outside air. Fine-tune any more charging with the can upright in the hot water and open the LOW side or blue line to let the refrigerant in as a gas. This is important because you cannot put a liquid in the low side you could lock up your compressor. Many videos incorrectly show you inverting the can and shaking it up or holding it sideways when putting refrigerant in on the low side this can damage your compressor. Hope this helps, good luck.

Thanks 👍👍👍 what you mentioned is a common mistake that most people diyer when changing can they didnt close the blue line 😂 and they think they have done it right 😁

Inverting the can of refrigerant charges the system in the liquid phase. In theory, this liquid could reach the compressor inlet reed valves and damage them. In practice, the liquid should "become" gas (due to the lower pressure in the lines between the can & the Compressor inlet...) But do bear it in mind.... do not blindly flood the lines with the refrigerant in the liquid state. There is a lot more to consider in theory than is explained here. Consider this as rudimentary first-aid at best.

Pulling a vacuum completes two things...# 1 it detects a leak # 2 when you pull a vacuum down below barometric pressure the air becomes hot enough to evaporate any moisture that's in it...

Thank you very much for your video it was very helpful because I was about to return my gauges because I did not know when you hook up your AC unit your gauges will move and you have answered the question please keep up the videos

i am iranian and thank you for your video.

Great video and explanation of the manifold. Sure a scale is best and all that stuff, but you can really get close with a professional set of gauges just as you showed.

actually back in the day ,the 90s when certifications were required to handle r12 and conversion kits were introduced ,that mineral oil in r12 was not compatible with the new pags,you would have to change the drier and flush the system completely,then add your new pag which is the oil after you vacuumed the system 6 ounces was the usual a tech would measure 6 ounces and stick the yellow hose into the oil open the low side valve and it would be sucked in and then you would charge the system.the conversion kit as i remember were only two quick disconnect vavles that screwed over the existing r12 valves.and back then brake fluid was used to flush the system.

Super camera job!

Great video. Great refresher. Very knowledgeable and professional presentation. Acts and sounds like he knows his stuff! Good job.

Best video, actually shows the behavior of the gauges from beginning to end.

Awsome video. I have to recharge my system and great to see detailed how too 😊

This is the best AC video I have seen so far and I was a mechanic !

Very good explanations here. Have watched several videos on recharging AC systems, and this one is great. Thanks!

You are awesome mister, I thank you very much for tons of info, makes me equip by doing DIY on my car ac system.😍

Lucky for me that my boy is a refrigeration and AC engineer and he can do mine!

If i looat at minute 07:13 i can see clearly that the lowe side vacum changed a little bit. Definitly some pressure enter back to the system on those t wo hours span, so i think you still have a leak. Regarding initial charge, there is two way to do it. The way you just did it's called, gas state charge, that is, in low wide open and gas can upwards, so you are filling with gas. and the other way is liquid state charge, in this way, you (WITH THE AC OFF) open only the high side valve and you turn over the R134A can, so you are injecting high pressure liquid to the system. In a perfect scenario, YOU DONT TURN OVER THE R134A can in a low side charge, because you are inyecting LIQUID TO THE COMPRESSOR and that can bend the pistons, it COULD happend, so its not very safe, to the compressor you can only deliver GAS! so you CANT TURN OVER THE CAN. After all the first R134A is gone, you close the high side valve and charge the second can in gas state charge by the low side. I do this high side charge because the initial can charges much faster this way.

Always wanted to know how to do this. Thank you!

Hi, You made a great video here. Thank you very much. I don't own a BMW which most of your video's seem to be about. I have a GM. However, A lot of your videos are very helpful though. This one is spot on :) I'm subscribing!

Excellent video. Thank you.

Very informative video for beginners. Good work .

you could flood your compressor with liquid and damage pump and or bearings that way .. gentle 12 oclock to 10 oclock then to 12 an 3 a few times then 12 for a few seconds

car work is so relaxing.

This must be the only set of gauges he has (not really) it doesn't take but the $14.99 set or single gauge you see that's already attached to a large bottle of 134 you bought 20 years back, which is a rip off but for ppl in a hurry or do it yourself ERS it's a good time as long as you know what you're doing. Don't over charge or you may blow the compressor. There's a good cleaner that is excellent for spraying into and through the fins of the condenser then after just a few minutes spray the cleaner with clean water from a garden hose, if you have access to the condenser look to see that the aluminum fins are straight, you may find there's a tool to help but it's a slow process but the better transfer the cooler your AC so that's your choice. Stay Cool n Stay Happy !

My AC wasn't blowing very cold and would only kick in that not very cold air after about ten minutes of driving in hot weather (90 deg). The clutch is engaged the whole time the AC is on. I vacuumed the system and only got a vacuum of 15 (or is that -15). I let it sit for 45 minutes and the vacuum didn't change. I then put a 20 oz can of refrigerant in (its an Audi A3 which I believe takes 19.6 ounces) and the air was colder (but it's only 75 degrees outside now). The hi pressure was up to about 150 on the manifold gauge and the low was about 40 on the gauge on the can (couldn't fill using the gauge set because I didn't have the right fittings). The air was noticably colder and the AC pipes were cold to touch the low and warm on the high, not hot but definitely warm. I then disconnected everything and let it run for a few minutes then re-connected the gauge set on both high and low. The high now read 125 and the low was 0. So I disconnected the low and connected the gauge from the can (having removed it from the can itself) and it read 40. I tried again and the gauge set (low) still reads 0. The can gauge still reads 40 when I reconnect it only now the high reads 100. I couldn't look for leaks because my refrigerant doesn't have dye, I have to rely on the vacuum not changing proving there are no leaks. Am I doing something fundamentally wrong ? Have the gauges suddenly malfunctioned giving the 0 reading on the low when the can gauge reads 40 ? All the time I had the engine running with the AC on full and I also noticed that the radiator fans were going into overdrive every few seconds. Another thing I tried was hooking up the gauges and opening up the low at the gauge set manifold to see if any pressure came out, none did even with both low valves wide open. Assuming there is an issue with the low on the gauge set why is my high only 100 when the can gauge reads 40 ? Compressor, orifice valve ? If the gauge set is not malfunctioning (it seemed ok until half way through this process) then what's going on, how is one gauge connected to the low reading 0 and a different gauge connected to the same port reading 40 ? Hope you can offer some suggestions. I'm at a loss.

Draining the oil. A lot of compressors actually have a drain plug for getting oil out. If it's been more then 5 years and your system is empty, it's a good idea to change the oil. Any time your system is empty for what ever reason it's a good idea to change the accumulator and filter. Any good shop that services your A/C will evacuate the system, change the filter and service it back up charging you ONLY for what refrigerant it required to top off. The machine will recycle/re-use the refrigerant.

Not opening the high side valve (the red one) when recharging the system was mentioned, but not the reason. The reason is that doing so allows the high pressure from the condenser to get into the can of refrigerant. Those cans are not made to take that kind of pressure, and could explode! When the can explodes, the refrigerant is instantly going to vaporize and freeze anything it contacts, such as clothes, skin.... eyeballs. The red valve should be open only if the vehicle is not running, such as when checking the static pressure to be sure it is equal on both sides of the system, or when pulling a vacuum. Otherwise LEAVE IT CLOSED!

Bro you brought this video right on time. I have a Caprice classic ‘96 and I want to know what the standard operating pressures should be? Thanks in advance

Awesome Video Mate

Great video. Thx so much.

I have a few problems. The compressor said it didn't ship with oil. To be sure I tried to drain it. A few drops came out. One instruction was to fill the compressor with oil before installing it. I tried this and it would not hold the 150 ml without overflowing. Yes I turned the compressor by hand while filling it. Second problem: I was careful not to "overtighten" the hoses on the manifold gauge set. I got them as tight as I could by hand. As I was filling the refrigerant I needed to turn the gauge set for a better view as it hung exactly like you have yours and the high side hose started blasting oil/dye and refrigerant. I closed it up again but I have no clue as to what was lost by amount. Long story short I still have no functioning a/c. New pump, new condenser, new drier, new expansion valve. High side is spiking at 300psi. Compressor kicks off and wont come back on until I shut car off and let system reach static pressure.

Super helpful. Thank you!

The most accurate solution in charging the hvac system is by measuring in weight,because the refregirant enthalpy will diff depending on your altitude from the sea level

You should always confirm the leak, before just replacing a part. Easiest, was to check your schrader valves is to spray soapy water mix on them. No high tech equipment needed.

Superbly informative pro video, thank you. Answered a myriad of questions..now I know thanks to you..:))))

great demo 🏆 thanks boss 👈

The most common r134a pressure vs temperature charts that I see online show different pressures than this, for example at 80 F they show 40-50 psi on the low side and 175-210 on the high side. Do you know why your chart is different than that?

Great video! It is my understanding that the reason you needed to evacuate the system by a pro, or at least back into a recovery bottle was not to release the old R12 into the atmosphere. This is why they came up with R134A. This should not be an issue since R-134A. It does not do damage to the ozone layer in the atmosphere as R-12 did. Also, you might have a very small leak from the small O rings that connect the pipes to each other. If that is your problem they should be changed. However, this is a pain in the butt depending where that ring is, there are a few of them. usually with a very small leak your AC should work for a few months if not the season. At that time just charge it again. About the valve leaking, You might want to push in the schrader valve with a small screw driver. Just a quick push and release it. Sometimes some crap gets in there and "popping" the valve will clear it for a better seal. Also, when removing the valve any charge or pressure in the system will be lost. When you turn the can upside down, Be careful. Car compressors do not like it when liquid goes into the system. It "can" destroy the compressor. Always use the can right side up for gas. When the can starts to get empty, meaning there is not a lot of pressure in the can. What you can do is get a small pot of warm water and insert most of the can in the warm / hott-ish water. This increases the can pressure and forces the gas out of the can much easier and faster.

Excellent instruction. Thank You.

nice video my friend... very well explained..

Shouldn't you also purge the blue line line at the connector on the A/C system? Believe that line was also exposed to the atmosphere when you changed the schrader valve.

When do you add the oil? My condenser had a hole and leaked all of the refrigerant out….got a new condenser, refrigerant and a vacuum pump. I saw you mentioned oil in the video, but not when to add it.

Awesome video. Thank you for making it.

Most cars have UV dye in them from the factory...It says so right one the charging weight sticker under the hood....

Awesome video thanks. Also to note you show how to bleed the yellow hose when adding a can of refrigerant! Great Job!!! This was very helpful!

Great video,thanks

Great video. Wondering if you can tell me if 36psi on the low side and 175 on the high side at idle with a ambient outside temp of 63F is ok for a 2010 scion xb. I would appreciate it. Thank you again for the great video.

9:04 "So I'm just doing a quick vacuum right now, I don't need to do it for 30 minutes because I already did that before." Wrong! When you let air back into the system, you bring with it moisture. Blow up a balloon with air, then let the air out and look inside. You will see lots of moisture. When you bring the system back to atmospheric pressure, you bring back a lot of moisture, possibly more than there was before you even vacuumed it. You must vacuum it all over and I would do it for at least an hour or more. Ever own an air compressor? Ever open the drain at the bottom to get the water out? That water all came from the air.

I usually coat my valve cores and o-rings with PAG oil. I was wondering, since you just installed them without any, did you experience any subsequent leaks?

thank you for video very helpful, i m about to do in my Mercedes !

14:29 is all most of us need to know

Great video!!! Bought one of these manifold gauges and never used one. My A/C never gets very cold. Tried a can with an included gauge. Said pressure was a bit on the high side. If I drive down the highway it gets a little colder, but still doesn't work good. Any ideas???

Hey 50sKid... love all your vids. If I let all the r134a out of my system and vac it out, will I need to replace the oil. I'm handicapped and trying not to have to pull the compressor to dump the oil and refill. Thank you for your time. Johnny

the yellow hose has a valve in one end? which way does it install?

Good work bather

Valves or orings. Evacuate, pump nitrogen, co2 or air inbthe system and start looking spraying with the soapy water. Water will evaporate at -35inHG

The vacuum contamine the admospher?

very nice video thank's for sharing!!!

Sure never open the high side but nobody says anything about that red valve on the hose. Is it in or off when filling?

Very nice job there 50sKid. Learned a lot. I have always been curious as how to bleed the actual low/hi hoses AFTER service is completed. When disconnecting low/hi couplers from car, the manifold gauges are still reading pressures. How do you zero them out once off the car?

great video what brand and model # is your gauges i will like to get same ones 😀🙂

Hi Jason, great video as always. My low side was around 70 and my hi is 150. What am I doing wrong?

that was GREAT. Thank you!

That is the only chart I have ever seen that the pressure is realistic. Every other chart overcharges a system having 50 Psi on the low side at 90 degrees. That is a 60 + degree vent temp.

when you prime the yellow hose...isnt there still air in the blue hose? doesent that need to be primed as well?

how are you supposed to check for a vaccume leak whaen you closed your gauges to the system and always charge ac on high side or static pressure un less the ac clutch is running

Awesome vídeo, very nice hints, you bet...

thank you soo much i appriciate your video

Thanks your video was the only one I found that addressed the oil issue. I had a leak from an o ring at the compressor line. My system hold 6.75 oz of oil. I wonder if I need to add any oil or how much was lost. I saw a small puddle underneath the truck. I wonder how much oil was in it or was most refrigerant.

Hi dear sir:excelent teaching and prophesional,thanks. Yours sincerly:peeno

Do u hv to close the tap in high pressure line (red wire)before inject UV dye for checking leaks?

Great job

sir i love your vidio hands down

Thank you, I just filled my semi truck your way

Where did you get that blue adapter and what's it called

my car has an ac leak. i need to inject dye in it. Car still has refrigerant in it ...how do i know when to stop as i dont want to overfill it? I have no idea how much is in there still. There is a general rule when to stop based on pressure?