Part 1. How to properly charge an auto AC R134a refrigerant air conditioning system.

[wowcolors]

Do you vacuum pump out of the high, low, or both sides?

[mikecarter79]

@wowcolors both sides

[skip4309wtf]

You can't charge on the high side when the compressor is operating because the compressor produces more pressure than what would be in the refrigerant can. If your a professional you KNOW when to dump liquid in the high side if you know what I mean (usually residential and commercial apps).

[oabus]

excellent how to thank you. I only wish i saw this before i charged my jeep. you state never open the high side when charging. if that is done will there be any damage to the gauge set or to the ac itself?

[Iceman20004]

Actually R134a is Refrigerant and is made by Freon, Freon is a company name I believe its owned by Dupont. and he is 100% correct on the Warm Water Technique. It is a good Idea to " pull " a Vacuum down to 500 Microns. and as for the gauges you can only bring the Vacuum to 29.99 In of Hg ( Hydrogyrum ) liquid metal or Inches of Mercury. I only want to inform everyone who watches this AWESOME video a little more of technical stuff.

[SCBianchi]

Lol@people who go from ac video to ac video to say 'R134a is not freon'

[TheNINJA33301]

How long should I vaccum and to what negative pressure?

[NerdForMIT]

2 Lbs very small, mine is 3.75+ Cause you always have to give a little extra when it deals with a completely bone dry system.

[Kill4MyDaughter]

Dont forget to purge your lines dumbasses.....

[meithkiller]

Thanks for your videos on this subject.

[bfcking]

This guy takes the time to record a useful video, and all you guys can do is hang on one word? Give props where they are due - Thanks for the video...

[jahotrod]

Thanks for the video. This really helped; just replaced the compressor on my truck. Great video and a down to earth approach.

By the way---Freon is Freon is Freon. It's been Freon my whole life and it always will be...

[Parsec994a]

Thanks for the video! I'm certified for Freeze-12 refrigerant, and I see people on forums and various other places first flaming people, and then giving out wrong info. I call it FREON too! Ignore the jerks, keeping making your videos!

[hensocr]

r134a is not freon

[mikecarter79]

@hensocr You are a genious !!! Thanks for playing .

[UrbexNW]

How do I add Freon to Buick Suburban? Oh wait, R-134a was never ever sold as Freon anywhere in the world... I mean GM makes Suburban but never sold it under Buick brand, but after all, brand doesn't matter right?

[mikecarter79]

@UrbexNW You know you sound like an idiot. I know that freon and R134a are different. I am just used to calling all automotive refrigerants FREON.

[UrbexNW]

@mikecarter79

You know, I'm just used to calling all automotive fuel "gas" be it diesel, propane, electric or whatever.

[womackke]

@mikecarter79 He does sound like an idiot

[ClipsForGames]

Thanks so much you help me and my dad out so much.

[pbtstyle]

It this the way to charge your A/C in all vehicles? What about a 2000 Honda Accord?

[1974mck]

Thanks. Very helpful. How much R134a should I plan to have on-hand to completely recharge an empty system on a 1997 Honda Civic? How much PAG oil?

[mikecarter79]

@1974mck For a COMPLETELY EMPTY SYSTEM, the '97 Honda Civic calls for 23 oz of R-134a refrigerant and 5 oz. of PAG-46 oil.

[SubaruB4RSK]

You know what I noticed Mike.. stupid harbor freight gauges... In order to charge the system you have to screw close the quick connects.. I happen to notice my can starting to ice up as I did and the low side pressure started to drop and went up as I brought up the rpms. I think I wasted about 2 cans...

[SubaruB4RSK]

The pressure was still high when I closed the valve on the gauges so I was wondering if something was done wrong?

[mikecarter79]

@SubaruB4RSK This is normal. Even when you close the valves on the gauge, you will still see the pressures from the High and Low side. When you close the gauge valves, all you are doing is shutting off the passage or connection to the YELLOW line. So, if you just want to go out and monitor your pressures and not add freon, you should close both the blue and red valve at the gauge.

[SubaruB4RSK]

So I charged doing only the low side today.. it took a little while but I finally got the pressure switch to turn on without me having to jump it (as I was leaving because of a storm) Anyways I still need to put in another can but what concerns me is when I turn the valve open for the low pressure with the car running the gauge shoots to like 90 psi or so.. should it take awhile for the high pressure to go up? I ask because when I ran out of the 1st can and closed the valve and tap the pressure

[mikecarter79]

@SubaruB4RSK You say "the low pressure with the car running the gauge shoots to like 90 psi or so". The important question is : Is the compressor running ? If the compressor running. Is this 90psi on your Low side ?  90psi on Low side is too high IF the compressor is running. Your High/Low pressures will also be affected by the ambient outside temperature.

[mikecarter79]

@mikecarter79

Here is an example of the kinds of pressures you should see at 90F outside temp and 50% relative humidity :

Low side : ~34psi

High side: ~295psi

Your center duct temperature with above conditions should be ~59F

(The above assumes a properly running ac system, and that it is running when these readings are taken, and the compressor is engaging)

[SubaruB4RSK]

Well I did everything... pulled a vacuum for 30 min I added a single can to the high side as a liquid with the car off the gauge got to around 105 psi and that was all it went to.

I disconnected the hose and charged the low side to around 40 psi with the car running and the compressor still wont cut on.

[mikecarter79]

@SubaruB4RSK With the compressor not working, the High and Low side should settle to equilibrium and the pressures should read identicle. Check the pressures again, and see if they are the same. I assume the 105psiH/40psiL where seen at charge time. If your car has a Low pressure switch, you can jumper the 2 contacts to the switch to test the compressor as well as the switch. The Low pressure switch is obviously located somewhere on your Low side line, usually near the evaporator.

[SubaruB4RSK]

@mikecarter79

thanks man for taking the time to help me I don't understand why it will not equalize with the engine OFF I give liquid to the high side which depending on temp around 105-110 PSI I sat for 20 min with the can in my hand and nothing changed on the gauges at all low side was still showing a vacuum. I can jump the compressor and it will turn on. Should I try and jump the compressor and then switch to the L pressure and fill with vapor so it will force vapor in the system?

[mikecarter79]

@SubaruB4RSK First, since the engine is off , the 105-110psi your reading is telling you that the pressure on the High side is equal to the pressure of the refrigerant can. You will only be able to put in a small amount of freon in your system when the compressor is NOT running. The ac system has to be operating in order to get a full charge of fron in the system. With that said, the 105-110psi should equalize across the entire system, so you should also see a pressure on Low side gauge.

[mikecarter79]

@mikecarter79 Now, first off, I am assuming you have the gauge hooked up correctly on the Low side. If you are not seeing any pressure there(again, pressure on High and Low should be equal with engine off) , chances are you have a clogged oriface tube or your Expansion valve is stuck in the closed position. Which one of these metering devices does your car have ? Do not run your compressor if freon is not flowing between High and Low side. This will seize the compressor because no PAG oil flow

[SubaruB4RSK]

@mikecarter79 My car uses a expansion valve (I will upload a video in a few)

[SubaruB4RSK]

@mikecarter79 Yes I have the gauges connected the correct way the high side does not equalize on the system when i charge the high pressure the low still stays in vacuum.

[ezkeyboardkid58]

how do you go about removing old freon or r134a and air

[Mooseboy240]

@ezkeyboardkid58 vacuum pump

[SubaruB4RSK]

Me again I was reading over my service manual for my car.. pretty interesting for the high side after vacuuming the system out I need to add liquid refrigerant into the system which I assume is turn the can upside down. and for the Low side it's vapor only with the engine running with the can tap up.

About 25 oz is full which is about 1.2-1.3 lb.

Last time I checked it was cold and snowy out which I think effects pressures.

[mikecarter79]

@SubaruB4RSK Well yes, upside down will dispense liquid, and can tap up will dispense vapor. With your system empty, and drawn down to a vacumm, it is OK to dispense liquid into the High side, since there is no High pressure.....Yet. When the engine is running and the compressor kicks on, you want to add only vapor to the Low side. The High side will develop pressures of about 200psi, which can burst a can of R134a. Adding vapor R134a to the low side is the safe way to charge any AC system.

[SubaruB4RSK]

@mikecarter79 Yeah I should be ok my system is fully discharged and I have vacuum it out a few times. I just have to go by what it says in the factory service manual.

Anyone who hooks up a can to the high side should stay away from working on cars period!

[borntofish559]

Hey can u make a video showing how to use the vaccum pump along with the gauges

[walker51f1]

how do you charge a system that has about 100psi pressure on the high side but the compressor doesn't run? At what pressure do the compressor start to run?

Thanks for some informative videos!

[mikecarter79]

@walker51f1 You will need to look at your low side pressure. The low side pressure determines when to cycle the compressor on/off. The switch contacts are closed at ~50 Psi and as long as it has that much, the a/c clutch should engage when you request a/c at the Controls. Those contacts remain closed until the gas leaving the Evaporator drops to 25 psi. At that number, they open up and power is cut to the compressor.

[mikecarter79]

@walker51f1 (continued) ...

The high side continues to flow into the Evaporator and any remaining liquid boils and returns to it's saturation pressure for the outside air temp. That extra volume causes the pressure to rise and when it reaches 50 psi, the whole thing starts over.

[mikecarter79]

@mikecarter79 (continued) ....

Now, the switches on the High Pressure Line are the High Pressure Cutoff and Fan Switch and the one, when disconnected, that makes the Main Fan run is the Fan Switch. A fully charged and functioning system shouldn't experience any more than 8 on/off cycles in one minute. A low charge, or one that is severely restricted somewhere on the high side will cycle very rapidly and easily exceed this threshold.

[mikecarter79]

@mikecarter79 (continued) ...

The gas that makes it into the Evaporator flashes off immediately and there's nothing left when it reaches the Low Pressure Switch so the compressor cuts out. What's left immediately returns to it's static pressure and in a nano second, it's back to 50 psi. An empty system doesn't do anything.

[eloid777]

where do u get the can tap value?... to go to the vaccum pump

[blackcloud161]

Ok I want to thank you for posting vid. I followed your instrctions and now I have frosty cold AC, Woo Hoo a big plus in FL!

[avionicswirenut]

Does anyone know how much R134A that a 2001 chevy Silverado Z-71 pickup holds?? I cannot read my label under the hood anymore.....

[TTLLOGIC]

Quit calling it freon, r134a is not freon.

[mikecarter79]

FREON FREON FREON !!!!

[SubaruB4RSK]

lol

[ohxietviet]

@mikecarter79 LOL

[Severalhands]

I find it's impossible to connect the hose to the high pressure port because of the pressure. What is your trick?

[mikecarter79]

I use a quick connect fitting. This type of unit first locks onto the high pressure fitting. Then you turn the valve which opens the shrader. You can get these at almost any auto parts stores.

[1967novawagon]

when you do the vacuum you open the high and low valves, but how come when you put the freon you close the high sides and only open the low side. is it ok to open both? also when you are doing a leak test which side do you put the dye on the high or low. thank u so much for your help i aprecciate.

[mikecarter79]

No, it is not OK to open both high and low side during charging process. The high side pressure will build up to around 200psi which has the potential of bursting the can of Freon. All charging of Freon or leak detection dye is done with ONLY the low side open. When you are vacumming system, BOTH sides are open because there are no high pressures to worry about. Keep in mind that the system must first be completely discharged before starting the vacumm process.

[4doorlife]

gotta love Harbor Freight...

[Ad4m2k8]

I hope you found a leak on that system before putting R134a in the system cause R134a is a ozone Depilation gas, and you can find this out if you can pull a stong vacum of 2 tourr

[mikecarter79]

I had no leaks in my system. I had a faulty expansion valve. Ozone Depilation, interesting concept.... Yeesh

[defendant420]

@Ad4m2k8 Yea thank God your leak wouldv'e caused the entire earth to deFuckulate and icebergs to melt and California wouldv'e fell off into the ocean.

[Ad4m2k8]

@defendant420 , if we all though relesing 500 gramms off R134a then there be millions off people doing it and millions off 500 gramms at a time is alot

[defendant420]

@Ad4m2k8 Yea

[MickeFamily]

@Ad4m2k8 -- R134 is 95% less dangerous to the ozone as the old R12 was. So, your tree hugging aside, it is not really that much of a concern if some R134a "accidently" makes it into the atmosphere. So, do your research and shut the hell up with your self righteous BS on youtube. People here are trying to have a good time for cripes sake.

[Ad4m2k8]

@MickeFamily lol i was waiting for a numpty like you to bite on my messege, and thinks he can be sciencetific, R134a isn't an ozone Depilation gas, its a single blend and has no ODP so how about you shut your mouth.

[TimKGrimes]

When you were vacuuming your system, do both Low & High valves on your manifold go open? Or is only the Low side open during vacuuming? I have the same vacuum pump. Thanks, Tim

[mikecarter79]

Yes, open both High and Low side to pull vacuum.

[cadirex]

Great videos!!!! but a quick question...if you replace a a/c part, when do you add the oil?

[mikecarter79]

You would replace the amount of oil that you re-capture from the component you replaced. For example, if you replace a condensor, you want to empty out the oil from the old unit. If 1 oz comes out of the old condensor, then you will want to add 1 oz back into the system. Use specified PAG oil for your application. The underhood AC sticker should indicate what viscosity to use. You can buy oil charge cans at any auto parts store.