AC Repair Kit: amzn.to/3WgsBo7 Tool Deals on Milwaukee, Dewalt, Makita & More: acmetools.pxf.io/9gRWRy Tip Jar: www.paypal.com/paypalme/bensahlstrom You guys are awesome. As an affiliate I earn from qualifying purchases.
I have been in the auto A/ C business for 48 years the use of a/c Dye is the best way because 75 percent of the leaks in auto A/c is intermittent due to expansion and contraction of all the aluminum parts and all the hot exhaust and water temperature repaid change I have the best sniffers that you can buy and use it first but most of the time we have to install a/c dye and bring it back at a later date and let it cool down and take all the plastic covers off put it on the lift and find the dye . We repair several hundred A/C jobs a season that is all we do
I had a leak in my AC system, turned out to be in the evaporator. What a PITA. It was my first ever A/C repair and after some research, I bought a set of cheaper digital gauges. The digital gauges can calculate superheat and subcool internally, and allow for switching between automotive (R134A) and residential (R410A, etc) refrigerants for the calcs. I found most analog gauge sets have dials for one or the other. I used dye in the system. A leak detector may have been useless because the evaporator is inaccessible behind the dash. After a month or so, I saw signs of UV dye coming from the evaporator condensate drip/drain line under the car. I can't confirm, but I read somewhere that some car manufacturers put dye in the system at the factory from new. I had to add R134A about once every 6 months before fixing the leak. The method I used was to first verify that there was a large difference between superheat and subcool temperatures. Then slowly add refrigerant until the superheat and subcool are within about one degree of each other. Typically it took about 2/3rds of the factory charge.
Thank you for CLEARLY EXPLAINING how recirculation and ambient temperature affect the pressure reading on the manifold gauges! The chart that you share at 2 minutes is a valuable resource that will be very helpful. Those areas had me a little confused until I watched your video.
I've been doing HVAC for 8 + years now. Car HVAC systems used to come pre-charged with dye. So yeah, dye is designed to be in the system. Dye is one of the best and easiest ways to find the leak. It mixes with the refrigerant oil and is A-OK to be in the system
WELL DONE! Car Guys should watch this just to refresh their memory. Save this video to watch, the only thing I would add is to use goggles when working on the AC.
All car compressors are designed to leak a small amount of refrigerant to keep the outer seal pliable. Adding several oz every few years is not out of the ordinary. Also, good mention on checking condenser’s coils for blockage. Many times on very high mileage vehicles (200k +) the condenser’s coil fins are smashed closed. This will cause the high (liquid) side pressure & temp to run much higher than normal. May need a condenser replacement or lots of patience in straightening the fins to allow proper air flow/ heat transfer when high pressures/ temps seen on liquid side.
I was going crazy trying to find out why my high side was so high that the safety valve in the compressor was releasing refrigerant. I replaced expansion valve, condenser with no luck. I was about the give up until I decided to check the radiator fan. Turns out I replaced the fan a couple months ago and never checked the direction of the airflow. It was reversed so it was blowing through the radiator then the hot air was hitting the condenser which was heating up the refrigerant and causing super high pressures. A reversed radiator fan can cause high side pressures to be insane. A simple wire swap fixed the issue.
@@jima3129 The fan motor I ordered off Amazon had the red/black wires swapped on the plug. I assumed it was correct since it was basically spinning and never checked the airflow direction. Never assume with aftermarket parts.
I’ve been in all the businesses that Ben works on and I can tell you that this kid is spot on with everything he does and if you have a problem and he has an answer pay attention because the kids pretty darn bright! 35 years heating and air conditioning Been retired for 12❤️🔥🇺🇸
Thanks for clarifying the ambient temperature. Most videos say the pressure should be between 25 and 30 on the low side when recharging and about 190 on the high side and they don't say anything about the ambient temperature. The temperature here was about 102 degrees and my pressures were high around 40 for the low and 210 for the high but I had barely put any from a 12 oz can. It was still not blowing cold air. I put in some more and it started blowing cold air now my high is around 250 and the low still around 40. I will check it at a lower temperature later to see if it has a lower pressure. I was afraid it was too high. Maybe it needs some more.
Great video as usual....FYI not only do the automotive quick disconnects make it easy to connect, they usually have open/close valves right on the quick connect hose fittings so you don't actually depress the schrader valve until you turn the knob in after your connected...
@@BenjaminSahlstrom yeah, that's true...afaik they are add on so they can be bought separately to just screw on to the ends of your gauge set hoses if it didn't come with them. 👍
When I attach the quick disconnects, I make sure the needle in the quick disconnects are fully withdrawn so it doesn't push/open the Schrader valve. Once it's connected, I turn the handle in so it opens the system and allows gas to flow. If you didn't buy gauges with handles, replace the set.
Nice work Ben, I've done my research, did everything by the book and had fantastic results, even after replacing components like an evaporator, (NO easy task in today's cars). I use all OEM parts, proper oil and amount, system evacuation and such. I also had no R134A to reclaim so that wasn't an issue. I even have a scale to measure the refrigerant. One thing I noticed on your setup, looks like you did a liquid charge vs a gas charge, when is one desirable over the other? I'm also with you on the sniffer over the dye.
If the jug is inverted like Benjamin's example, you can overwhelm the system by introducing too much R134a so monitor the low side head pressure carefully.
All compressor will leak at shaft seal. Always add a PAG oil charge (walmart) especially if leak is low and leaking oil too, without oil compressor will fail. If you need to add 12oz a year system can last indefinitely. To fix a leak and evac system diy'er doesn't have equipment and more parts may have to be changed also.
When testing the car take the temperature close to the Condensor. Ijust because it 75 degrees out doesn't mean the fan is Circulating 75 degree are. It's likely warmer. The other option is doing it when it's windy or use fans to move hot air away from the condenser. Oh and I know with R134a prices going up don't use propane. I yes it works better, but is flammable and you need a lot less and you would have to accidentally vent all the air to the atmosphere.
Great video. The remaining freon in the high side/low side hoses is significant. How do you put that into the system once you are done OR if you hook up gauges to check the system?
Pressures are dependant on clean evaporator core clean condenser condenser fans working orifice tube or Tx valve variable displacement maybe ecu controlled fixed displacement When charging use weight method with scales u did excellent pressures are almost are individual to each model pressures are changed by design or fault if correct charged The ambient temp can change pressures have all doors open when charging to load a/con have on recirculation ,, sucking in air from engine bay is not normal check pressures at idle and 1500rpm THE PRESSURE CHART IS WAY INCORRECT 115F DAY 25--35 PSI LOW ,,, 150--160PSI HIGH at idle and 1500rpm txv and fixed displacement compressor
Automobile air conditioning systems operate as medium temperature refrigeration systems. You should have around 22 pounds of pressure which would give you about 25° of saturated temperature of 134 the ambient temperature only equates to the pressure temperature of the refrigerant. At 85° outside we would have about 95psig of pressure in the refrigerant bottle. That ambient pressure does not equate in the automotive system because you're not measuring subcooling nor superheat. An expansion valve is not the same as a TXV capillary device nor a piston. I'm no wizard, but my 16 year old truck puts out 40° out of the vents
If you're going to use the pressure/ambient temperature charts (or scale on gauges) beside turning OFF recirc' you should use a piece of cardboard or similar to block engine heat airflow from being pulled into the air box and across the evaporator. That means BOTH sides of the cowl vents need to be blocked from sucking hot condenser and radiator air and blowing it across the evaporator.
I have been watching tones of Car AC refrigerant charging video no one talked about air circulation position that amazed me because in those videos big RU-vidr included.
i thought the same thing. i charged my fiancés car a couple weeks ago and she a day or two later she complained about the ac not staying cold and it turned out it was overcharged. likely because i had recirc on
Using Dye will not harm anything. Nor will using stop leak... they are both made to be added to that system. There is no such thing as 'cheap' R134A as it's being phased out and as time goes by it will cost more and more. I do love your videos though!! Keep up the good work.
If you draw down a vaccum forget about trying to reach certain pressures. Always go by weight. Get a cheap digital scale and if the system requires 34oz give it 34oz and ignore the pressures unless they are sky high
I work on MVAC, fan speed always on max and put recirculate on...ALWAYS. The same with a house do you open a window when you're charging a house? JS lmbo. Now as far as dye, it works well and I find it better than a sniffer just my opinion and if your look for a leak with dye if you don't want it in there flush it out, I mean once you find the leak you have to take the freon out anyways to fix it. I honestly think you did well even with a scale. I don't use scales I use a temp gauge and if it's a healthy system I can get normally 39 to 42 degrees coming out the vent. as of 2024 this will be the last year you can buy it everything goes to 1234yf. Be good bro
My life used to be so simple. I never thought about air conditioning at all for decades in western Oregon and western Washington. I hardly thought about heaters, or ventilation. I’d sleep outside even in winter sometimes. As kids we roamed freely. Then I lived in a van with no heater, water, etc. Now this crap is all I think about lolz. It’s good brain exercise I guess. But there sure a lot of crap to spend ones money on. I used to spend a lot more time going out exploring the woods and fishing. Now it’s spent taking care of all the stuff I bought lolz.
if I'm not mistaken, I'm sure I've heard in a video by eric the car guy, chrisfix... someone, who stated that new refrigerants come with the dye already imbedded in the gas to help located a leak. I'm 90percent sure on that fact.
Do you ever clean under the hood? Dirt will wick plasticizer out of plastic parts, making it brittle and prone to crack, then you get leaks, then you have problems that are very hard to locate. I actually use a pressure washer to clean, and apply protectant like armourall to hoses and plastic parts. 2004 f150, 164,000 miles. Runs like a swiss watch. 😊
Look into "Strike Hold" Dry Lubricant Protectant, see their Video, can be Sprayed Directly into Electrical Componants while Running. Alternator, Electric motors, battery Operated Equipment, Generators, Excellent for Firearms.
Please do a video on changing from R-12 to 134A, show all the steps and what all the pressure readings should be to get the 134A car vent temps as low as the R-12.
R134a is getting phased out . There are a lot of R12 alternative, use to get them at auto parts stores. I bough a bunch a decade ago from Canada. you can still get Envirosafe online but the prices keep going up. You need half as much as your R12 system says and they say you don't have to vacuum the system. Eventually all the safety nannies will allow cars ACs running on R290 or R600a. Might take a decade.
@@MichaelMantion "Eventually all the safety nannies will allow cars ACs running on R290 or R600a. Might take a decade." We can hope, but I think you're being overly optimistic.
They sell R12 to 134a conversion kits. Recover the R12 to an approved container. Weight the recovered R12. If there is any oil recovered, weight it too. Pull a vacuum on the system and close all the valves. Shut the vacuum pp off Record the vacuum reading. Go to lunch for 1 hour. Did the vacuum reading drop significantly or held vacuum. A decayed reading indicates a leak. Refill the system with nitrogen gas. Add dye. Replace the bad part and retest. If the system held vacuum. Obtain the specs for the vehicle you are working on, that will tell you how much in Oz to fill the system. Get a scale and add a can to the yellow line. Open the tap, depress the small valve 2 sec to burp any air out of the line. Open the blue or suction line and start filling the system. Start the vehicle. Set to max cool. The AC condenser cooling fan should start. Observe the AC clutch cycling as you fill system. Fill the system to the specs for the vehicle you are working on. Make sure the condenser is clean also. You may need to wash it out.
I converted my 68 Chevy to r134. Evacuate entire system. Vacuum Drain and refill compressor to specs. It’s just of matter of changing the hoses. And I’m using the original Harrison compressor. The cooling is almost equivalent. I did install hi/lo pressure switch. Add the same amount of r134 Freon according to manufacturer specs, located on compressor tag, mine is 36 ounces. EZ.
Would have been nice to show & tell how you charged it. Noticed the can was upside down, if I remember that lets the liquid in. Were you adding on the high or low side and what was the method?????
Thank you Ben.. Sure enough the cabin filter was clogged with leaf debris . Thank for the smack in the back of the head...I should of thought about it but didnt know that the van had one behind the glove box.. Fixed.....
I've got a situation on my 2016 F250, 6.2 gas. This year for the first time 137k miles, when I come to a stop the AC heats up, as soon as I get to speed it cools down. My gauge showed low on R134a, so I added some not much, and the pressure was ok. But still the same situation happened. I don't have a condenser fan, just a cooling fan. If you have an idea where to go next, I would appreciate it. Great video by the way.
Clean the condenser and the radiator. Wash both of them out with a garden hose. When I did my daughter truck. I used dawn dish soap. Used compressed air to blow out any remaining debris.
If you have an engine driven fan with a fan clutch, check the fan clutch. If the fan clutch is bad it may not be spinning at full speed . That will cause poor A/C performance and high refrigerant pressures at idle.
It's actually fairly difficult due to inside fan speed choice and outside condenser condition, fans and temperature. Don't run the inside fan at full speed but do run on recirculate. Recirculate is the only position that should be used unless the inside ambient temperature is above the outside temperature, this is what that feature is designed for. (Unless Bubba let's out a giant fart) Master Ase and IMACA certified instructor...
So, his advice (to not use recirculate while measuring pressures) is incorrect? In that case, what ambient temp do you use when trying to decide what ideal pressures are? Shouldn't your choice of ambient temp for looking at gauges be the same temp that is entering the evaporator? If you use recirculate, your ambient temp for the condenser will be correct, and the temp for the evaporator will be colder than ambient temp suggests, confusing gauge interpretation.... HVAC techs would measure temperatures at both coils and calculate superheat, but in the automotive world we don't have those fancy tools.
Be very careful about keeping AIR out of your system. Purge your gauge lines before hooking them up. I actually installed ball valves on the ends of mine to keep them completely sealed. The Schrader valves are a highly likely source of refrigeration leaks. They should probably be changed out if there is any significant leak in your system.
I'll evacuate the system and put 100 psi of nitrogen to it, then squirt a solution of water and Dawn soap on the hoses, connectors, compressor seal area and condensor with an ordinary spray bottle. You'll see the problem area quickly where you see bubbles.
In my Subaru's factory service manual it says to set recirculation to ON and open all windows. I would really like to understand why this all matters. Thanks!
I saw your pressure chart that shows about 340 psi at 100 degrees. I've found quite a few charts that show 100 degrees closer to 120psi and that's more inline with what is on the front of my manifold set. How do you know which chart is correct? The app from the Freon manufacture (chemours) states about 135. 135 seems low to me but who would know more than the one who actually makes the refrigerant? Edit: finally charged. 2,000rpm. 40/365 with 128 degree condenser air inlet temp. 158 degree high side line temp at pressure tap. Upon test driving, 40 degree outlet temp.
Hello Ben: So I have a question that I believe is closer to your area of expertise. I have a mini split, but it is a 24 volt system that uses a variable frequency compressor that I use in my RV. These are designed to be energy efficient, but they probably don't produce the same kind of output as a traditional one speed compressor would. I can tell when the compressor is at max speed just by the sound, and I can also confirm by the wattage being used. I'm assuming that low pressure and high pressure readings are only valid when the compressor is running at full bore--correct? For an automobile I don't think this is even a factor, the compressor is either on full output or off. Since the head unit or evaporator is indoors (Inside the RV in this case) I'm assuming I should be using the indoor temperature and not the ambient temperature outdoors. Alternatively I guess I could open the doors in the RV so everything is the same. Since this test is based on ambient temperature, this seems to be a critical factor so I wanted to ask for your suggestion. In my experience with this mini split, it only produces the extreme cold temperatures very briefly when the compressor is at full bore, and then it's cycles back down again. I think this is a trade-off for energy efficiency as this runs off a battery. Nevertheless, all the more reason to get it as cold as possible. Again I just wanted to ask about where I should be taking the ambient temperature reading, because I'm talking about a mini split, and then I'm also assuming that the pressure is only valid at full power on the compressor. I've even seen guys with automobiles rev the engine up to 2500 or so to get the readings. I think you're just using idle speed, so that part is a little confusing as well. Isn't pressure going to go up on the high side with higher revs and the low pressure lower? I don't know which one is correct, but most Mini split systems only have one speed. My situation is a bit unique here with a variable frequency Compressor, but I think the basic concept remains the same. Your comments and feedback Appreciated.
I just filled with a can and the aircon stopped working.I started bleeding from the low point seemed warm air was coming out,then suddenly cold gas and it started working again.Must have been air in the system.
My truck’s low side pressure is too high. Freon is good and no leaks but it is not cooling. The mechanic said there is restriction and that I need to change the compressor and accumulator. The compressor is working it is just not cooling. What is your opinion on that?
It sounds like you have a leak. Best thing to do is pressure test with nitrogen, find the leak (s) and repair. Pull a vacuum on the system and refill with refrigerant
So the only correct way to determine anything with wrong with the system and while I'm typing this I see you talk about over charging it don't ever do this it's not the more the merrier! And there isn't capillary tunes in a car ac unless it's like 50 yrs old
What about if one car takes 850grams of refrigerant & another only takes 450grams ? Is that pressure chart accurate/universal for any charge of refrigerant or a particular charge ?
The chart should be accurate regardless of the amount of refrigerant a particular system is designed to hold. The pressures should measure/register based on the ratio of refrigerant to the overall volume and based on the ambient temperature. I'm not an actual A/C tech but I have stayed at Holiday Inn Express a few times.
My truck's ac blows cold but barely to the point that I have to drive with my hands on the actual ac vents in order to cool myself down. The problem is that everything in my ac system is new, except the evaporator, all other parts have been replaced. My pressures show normal low side but high high side but in my case the orifice tube is new and shouldn't be clogged at all. What else can be the problem? Thanks!
Evaporator core plugged. When the AC is running. The evaporator core will develop condensation. That's why it has a drain. Because of the condensation, if there is any dirt. That's cakes up the evaporator core.
When doing a recharge with a manifold set- I'm guessing keeping the high pressure coupler value should be open? But the high pressure value on the manifold is always closed while the vehicle is on + compressor on. Is this correct?
Was the lines broken? Condenser busted. Did you replace the metering valve that goes into the AC low press line ? Are the cooling fans running. Is the AC clutch cycling Have you changed the cabin filter
I would rather buy a small bottle of DYE that is perfectly fine to put into the system and find a leak then spend $340 which is the equivalent of about 34 cans of refrigerant
Hi sir. I have a three doors True cooler that uses R134A gas. If the temperature in my store is 75 degree, what should the low side pressure be? Please help. Thank you.
I thought if you turn it upside down like that, that liquid is suction to the low side and that’s bad for the compressor. R134A is a GAS not the liquid.. I confused as to why you’re filling it like that.
Hey Ben, Rookie question- I noticed some of the manifolds like yellow jacket and Mastercool don't have the sight glass on them, but they look sturdy as hell.. Is the sight glass needed for pulling a vacuum etc?? Thx
@@BenjaminSahlstrom Not sure, but they've been doing it since the 90s as far as I know. The dye actually comes in the accumulator, and mixes with the compressor oil.
Use a pressure chart at your own likely catastrophic risk to your entire auto HVAC system; it is not accurate. No mention here that humidity is also a factor in the chart. Any attempt to add refrigeration is fraught with risks which could exceed mfg quantity specs, resulting in super high pressure and compressor destruction. Modern vehicles auto AC is measured in volume which should not be exceeded. The entire system should be evacuated. Detect and fix Leak. Drain and refill compressor with correct amount of PAG and use PAG oil with UV dye. Losing “Freon” means you’re are also losing oil. Vacuum system per protocol. Only than measure and add charge vehicle according to specifications. ASE.
None of this temperature will work that you have described on variable valve compressor which is what all recent latel model cars after 2015 has it. The knowledge you have on residential will not work in Automotive because , fan speed, variable valve compressor , change in speed of air at condensor (based on car speed) all affect pressure and heat.
He is right variable stroke compressors work different can’t go by charts and pressure go by factory specific charge pump it in before you start the car a lot of the newer cars hold like .83 charge without a good robinair machine it is impossible to get the correct charge. And on the small units a once or two makes abig difference
If using a dye, check what the manufacture recommends. For example, there is only one brand of dye is approved by Honda and recommended by Honda for use in its vehicles. The claim is that other dyes may contain additives that might damage seals/gaskets and possible corrode other parts of the AC system. I would strongly urge not putting anything like sealers in any AC system.
Here is what I do that will horrify pros. When my A/C stops working, I stop at Walmart and blow a can onto my car. Than it works for a month or so. 2 or 3 cans a year is pretty cheap compared to A/C repair.
All these videos that suggest adding gas to the A/C system are false. You need to vacuum all the gas in the system, due to air contamination, then add totally new gas.
Lol so much of this is wrong you really should have not made this video but I love it when people do this shit I end up with the car at some point and I make money!
