AC System 101 Diagnosis & Repairing

we have one for you that you probably ran into a C's not blowing cold well with some simple gauge readings and a touch test we can fix that it's all about the air conditioned system on today's tech garage [Music] welcome the tech garage presented by taco parts now there's nothing worse than a see not working right specially here in Florida but no worries we're gonna take you through the complete a/c system today you know we're gonna learn about gauge readings we're gonna understand everything one of these components that are on this table here and we're also gonna do some Diagnostics and inspection now on our car I got a gauge set hooked up here now you can go down to the auto parts store and you get one of these they're relatively inexpensive and this gauge readings going to tell you everything you want to know along with that and the field test we can tell what's going on and just by looking at these gauges I can tell the compressors running it's not cycling and the gauges are at about ambient temperature we're gonna need a compressor on this car so in this show we're gonna put a compressor on but you know while we put a compressor on we're gonna have to put the accumulator and the orifice tube in as well but before we do any of that it's imperative that we recover the refrigerant out of the system John if you wouldn't mind shutting it off we're going to show you exactly what you need to do to do this in your driveway these are fancy set of gauges we've got some fancy tools but truly we're gonna package this up and show you how you can do it a lot of our viewers are restoring classics or hot rods or older cars and you need to dive into the AC system so investing in a quality set of gauges as John's mentioned has really good return on investment you can use them on multiple vehicles for a lot of years but step one is always to evacuate the refrigerant in some cases the freon out of an older system and that's where you're going to need the help of a certified technician what that technicians going to do is use a tool very similar to this to evacuate and capture all of your old refrigerant safely and dispose of it so you don't have to worry about that or any kind of fines that you might experience after that so step one we're gonna remove John's gauges here there's a high pressure line as he mentioned and a low pressure line we're gonna connect up our tool set these right out of the way similarly to the high and low pressure it snaps down on this is what your technicians going to do on your system now tighten it snap it down on tighten it good we're all sealed up we'll come over to the machine we simply hit recycle which is the same as capture or evacuate all of the old refrigerant in this system we tell it yes and we're underway now this process will take 10 to 15 minutes depending on the vehicle so while we wait for this to get evacuated John's gonna tell us how the whole a/c system really works no only a tech garage do we have a functioning AC system working on a board thanks to our friends at a tech but we have to understand the concept of air conditioning and we're gonna have to rewind all the way back to the beginning the job of the air conditioned is to take the heat out of the car and remove it thus you're feeling a little bit colder and there's an AC cycle we have to understand that makes that happen in all the components and we'll start right here on the compressor now the compressors job is to compress that's what it's doing is taking that refrigerant in the system it's squeezing it it's making into a high pressure and when it does that it gets hot so as it comes out you can feel this lines hot it's gonna go run over to a condenser now the condenser is located in the front of the car what the condenser does it change actual states of the refrigerant it left a gas it went in there and just like your mirror in the bathroom it kind of rains down when it starts to cool that's what's gonna happen here we're gonna take that heat we're gonna transfer it to the outside air and it's going to come out then a high pressure still but it's going to come out of liquid when it comes out of liquid it goes over to the actual receiver dryer which is just a desiccant bag that dries the refrigerant we'll take a look at that a little bit later and then it returns over to what's called a TX via thermostatic expansion valve now just think about we had high pressure in that system up to this point now at this point it's gonna go from a high pressure to a low pressure remember it's a liquid - so a high pressure liquid - a low pressure liquid when that happens the refrigerant becomes very cold and it's going to go over in a vibrator inside the car where your blower motor blows across it grabs the heat it's going to transfer from that into the refrigerant and it's going to take a ride from there all the way back out when it does that it goes through that actual evaporator it gestates once again we go in a liquid we come out of gas then we come out a low-pressure gas and we returned back to the compressor and that process starts all over again but that process has to work and I can actually demonstrate it right here with these gauges and this will be a really good example of what's going on with our Mustang now our gauges here the systems off and while the systems off you can see here I got what's called ambient temperature ambient pressure refrigerant usually stabilizes around ambient temperature this one's at about eighty low side the low side of the system is where that compressor is pulling the high side is where it's pushing so you can see my high side right here is about 80 so they're equal the system's equalized out you may shut your car off and hear it hissing Shh it's equalizing out that's what's going on from the high side to the low side but remember I'm gonna fire this up and when I fire it up the compressor is going to pull it's gonna pull the refrigerant on the low side so what we're gonna see is we're gonna see this gauge actually drop down it should drop down to about 30 to 50 pounds around there somewhere and then the high side is going to push it's gonna compress and it's gonna raise the pressure so what's going on there the high side is gonna raise up so keep your eye on these gauges when I fire this up I'm gonna turn the ignition on I got electric motor down here that's gonna run the compressor and you can see the low sides pulling which is the low side of the system Brian hooked the blue cage up to that earlier and the high side actually starting to rise it's going up because we're compressing we're raising up on the high side now on our Mustang what's going on is the gauge is really never moved but yet the compressor was running so on our Mustang the compressors not pulling and it's also not pushing it's not compressing the refrigerant in the system so with that happening we know we have to replace the actual compressor on our Mustang over here but we said before before we do that Brian's over there recovering the system how's it coming Brian okay we've got all of the old refrigerant recovered out of the system so it's safe to go ahead and open it up I'm gonna disconnect the RTI here we'll need it again a little bit later but we can go ahead and disconnect now both lines are clear and we've got the airbox removed for easier access now I'm going to remove the serpentine belt and again it's safe to go ahead and disconnect the low and high pressure lines from the back of the compressor so we can get this old compressor out of here in the new one end we'll be back right after this here's a technologically the in pressure of the refrigerant as it leaves the compressor a low-pressure gas B high-pressure gas C low pressure liquid or D high pressure liquid the correct answer is B the compressor changes the refrigerant from a low pressure gas to a high pressure gas and the refrigerant eats up as in pressure rises [Music]

Channel: DIYGarage bryangregorytv

Views: 402,221

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Id: 6ZoSAtf_m90

Length: 7min 57sec (477 seconds)

Published: Mon Apr 24 2017