Added: 2 years ago
From: mikecarter79
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  • Can someone help me:

    My car's compressor was shutting off because the radiator fan would not come on (fan motor WAS bad). I replaced the fan assembly and now that's OK. The AC was working for about a day after that but now it does not blow cool air. At first (before we discovered it was the fan assembly) my mechanic thought it was out of Freon. When he tried to refill it he used the high pressure line!! The low pressure port was by the compressor! Could that mistake takeout your AC system??

  • Attaching an inline Torr gauge would help determine when the vac process is complete. Then if it doesnt pull down to under two Torr (uk regs) or doesnt maintain the vac when you shut the lines off and turn the vac pump off you know there might still be a leak.

  • if you have to vacuum the system,but the system still have decent amount of pressure,let say 25 psi at low side,and 115 psi at high, can you still use this pump? great vide by the way, im just wonderin what pressures your vehicle have before you vacuum it..

  • I thought you only needed to vacuum pump out on the low side. Are you telling us it needs to simultaneously be on the low AND high side as well, because not all of us have a manifold gauge set.

  • @Moralvorstellung7 Both sides need to be vacuumed. Id imagine you could do it through one side but youd need a very powerful pump.

  • A/C Vacuum Pumps are used to remove air and moisture from an A/C system that has been worked on. If, for example, the A/C system has been repaired(compressor, condensor, evaporator, accummulator,or whatever), this is when evacuation is required. During evacuation, the air is removed from the AC system and of vacuum, the moisture begins to boil. The moisture now becomes vapor and is drawn out of the system by the vacuum pump.

  • You that you've got this up for the DIY'ers out there... But don't you need licenses to purchase refrigerant? Things may be different here in Australia, but I'd be quite sure that America (assuming that's where you're from with your accent) requires it too?

  • will i have to vacuum the system if all i did was pull the lines off near the radiator??

  • @jlinn91 Yes... If you have pulled any of the lines off, you would have let air into the system. Air contains moisture. Moisture can/will lead to acid and corrosion of your system. Not to mention you would have lost your refrigerant in the process of releasing the lines.

  • thx mike.

  • great video everyone was great help..

  • when you're "pulling" the vacuum, is your car on or off? I know when you are recharging the r-134, you need to have the car running and the a/c on.

  • @araki916 Vacumm = Engine Off , always.

  • @araki916 when vacuuming the car is off. When charging the system the car needs to be running with the ac on MAX.

  • My question is does the car have to be turned on and the A/C also have to be turned on during this process?

  • what hapens if i dont vacuum the system before replacing the compressor

  • How do I know how long I should leave the vac pump on for?

    one other thing I found that Big lots its like a thrifty store sells 134a freon for $8 and its the same thing as auto stores sell w/o the fancy adverting on the can

  • I just put freon into my 1985 ford truck and then the compresser went out(locked up and started smoking . Is there anyway to save freon to reuse if i get new compressor. I hate to spend $75.00 more to get more freon?

  • @msrlaw123 you need to convert to r134a, ask around like autozone. I replaced my r12 to r134a with a $12.99 fitting and the a of O I changed as well

  • @msrlaw123 Should recover refrigerant with a recovery machine when dealing with a charged system. It's the law. At least for us in the HVAC business.

  • @Hopefulheartz Yes, you should always recover your refrigerant. Good post

  • @msrlaw123 You would need to purchase a recovery station(expensive), or , call some local AC shops and ask if they can recover it for you and give you a discount when you go for re-charge after you have repiared your system.

  • When you vacuum the system do you have to recover the freon, if so can you reuse it

  • Great Vid. Mike my 2004 durango compressor goes on and off after warming up giving warm and then cool air. What should I look for? I am purchasing a hose set. It started after I added a little r134 cause the temp inside seemed cool not cold.

  • @kdspeiser You really need a gauge set to monitor your high and low side pressures to determine if you have too much or too little freon. You will need a Temp/humidity/high pressure/low pressure chart to determine what pressures you should expect on your gauge. Without gauge set, you cannot tell if you have too much or too little frean charge.

  • Mike...great video. I bought the vacuum and gauges from Harbor Freight (like you noted). But how do I pump out the R134 if I don't have a recovery system? You don't show a recovery system in your video and I thought it wasn't legal to pump R134 into the atmosphere. Did I miss something. Please help as I need to evacuate my system and recharge.

  • @Testnavewo In my case, I had a defective shrader valve, and all my freon leaked out, so I didn't need a recovery station. It is recommended that refrigerants, be it R12 or R134A, should be recovered.

  • So, if there were any refrigerant left in the AC system it would have escaped via which part of this setup?

  • @Testnavewo Did you figure out how to pupm out the refrigerant? I"m looking to do this myself, and having never done this I can use any advice? Mike do you have any advice on this? Thanks everyone!

  • If you evacing a system where is your freon going

  • the yellow hose on gauges will not fit on the lower pump fitting, did you modify yours.

  • wen u vacum everything out what should the gages say ?

  • @kjhhjhbcjdc The needles on the gauge will go BELOW the 0psi mark, which tells you that your system is in a state of vacumm.

  • @mikecarter79 Manifold gauges hardly give an accurate vacuum reading. Best to use a vacustat for proper evacuation, and get down to around 500 microns.... but I know, plenty of people just use manifold gauges and monitor the vapour coming from the vacuum pump exhaust :)

  • @kjhhjhbcjdc Depending on the guages you have, it will either go well below the 0psi park like he stated, but on some gauge sets they go below zero. Generally you will have around -27 or -28 lbs on a vacuum.

  • can I rent this vacuum pump

  • @kidcool1977 I am not sure. Check with Autozone or Advance Auto to see if they rent vacumm pumps.

  • @mikecarter79 yes you can Autozone rents the pump and gauges, i picked them up today pump was $200 gauges were $25 (you get 100% of the money back)

  • i rented the gauges and the pump from autozone for a $245 refundable deposit ymmv

  • Thanks... I will try it out. by the way, my other car that's been overcharged with freon is now working. I bring it back to regular 35psi and now its blowing cold air.

  • @stupid0388 Good job stupid , keep up the good work !! ( j/k , I couldn't help it, I love your username !!!! )

  • I have some questions sir, My system got overcharged on freon. Now its blowing warm air, do I need to evac everything until I reach empty? Or just bring it back to 35psi (normal pressure)... Please reply

  • @stupid0388 Just bring it back down to normal Low and High side pressures as you mentioned. No need to discharge entire system.

  • Thanks! By the way I have another car its 1985 Corvette with R12 system? Do I need to evac the whole system in order to fill it up with R134a? The guys at autozone doesn't know..

  • @stupid0388

    i'm not an expert, but I do now you will have to evac the system of all R12 before filling it with R134a. You will also have to buy a retrofit kit. Change out the accumalator and oriffice tube. also One more thing you must do is clean the system with AC flush. make sure you are only flushing the lines and condensor. Read the back of the flush container. I just did the same thing to an 89 oldmobile. hope it helps.

  • Mike, first of all, I would like to thanks you for the nice vid for us do-it-yourselfers. I am about to purchase a 2.5 cfm vacuum pump and it also says ........."Remember to purchase Enviro-Safe Vacuum Pump Oil along with the vacuum pump. Many A/C systems contain debris. In order to protect your vacuum pump from debris, we advise you to order a filter drier. In addition to this you would need a 36" hose.".....Mike are they telling the truth or just trying to vacuum more money out of me?

  • @jaydee427 Don't worry about getting a filter drier to protect your pump.... Rubbish, yes, they are trying to milk you for more money !!

  • @mikecarter79 can I rent this vacuum pump

  • I changed the compressor (locked up clutch bearing) and then added 3 cans of 134a. I did not vacuum the system as you have described....my system is now coming on (clutch/compressor) and fans are blowing (condenser) but all air coming into cabin is very warm....any ideas on what the problem could be and hot to rectify it? Tks

  • @gandl2123 You really need to get a gauge set and check your high and low pressure lines. Even though you did not vacumm the system, it should still give you some cold AC ..

  • @gandl2123 If you did not pull a vacuum and you added 3 cans of refrigerant, there is a good chance that you r AC is going off on "high head" pressure. Some vehicles are equipped with a switch that will prevent the compressor from coming on if the pressure is excessive and your scenario definately could cause high pressure..

  • I changed the compressor (locked up clutch bearing) and then added 3 cans of 134a. I did not vacuum the system as you have described....my system is now coming on (clutch/compressor) and fans are blowing (condenser) but all air coming into cabin is very warm....any ideas on what the problem could be and hot to rectify it? Tks

  • Mike I can't thank you enough for his video

  • @thybigballs R134 has a GWP (global warming potentional) OF 1400, Which means it is 1400x better at absorbing heat than CO2. It should be treated with as much / more respect as R12. It really shouldn't be a retail item, if someone has a leaky A/C it should be repaired, not just refilled. Seeing as the upfront costs are so much for the man on the street, I think it should be subsidized / free so that people just go and get it fixed, rather than pumping it into the atmosphere...

  • When I run vaccuum on the system, will it absorb the existing fereon in the system and a little bit of oil? Am I correct.

  • What is the fitting called that lets you pull a vacuum? Where can I get one?

  • where do you get the fitting that allows you to pull a vacuum? what is it called?

  • wtf? harbor fright shit again -_- a do it yourself more like a how to release more r 134a into the atmosphere and mess up the ozone some more, its bad enough we have idiots working on house A/C and releasing the refrigerant, now everyone is gona work on their car and release more this is BS - ____ -

  • @aman450r I am doing this on a totally depleted system and a video like this helps. I am NOT putting ANYTHING into the atmosphere.You should think before you blurt out your nonsense. Of course that's why you do it, so saps like me respond.

  • @aman450r R134 doesn't deplete or mess up the ozone, dummy. It is a greenhouse gas, though. You probably exhale more greenhouse gasses just breathing for one day. Hey, maybe you should quit breathing!

  • @aman450r I would much rather teach people to properly pull a vacuum and check for leaks than have them run to Autozone and dump another pound of 134 in the system every other month. And most of the time the system has already leaked out (as in this case) and you are not releasing anything.

  • hello I have a question after you hook up the low and the high vacuum holes into the car and the hoses are hook up the electric pump where does the excess moisture goes to?

  • Mike,  Is there a need to have the vehicle running? Thanks.

  • Mike, Is there a need to have the vehicle running? Thanks.

  • nice vid,  :) sounds nervous? is it cold there?

  • Still not sure about the black air knob (even though I have read the comments). Do you have to un-screw it while vacuuming the system? If so, how much? How long should it be left open? The directions that came with the US General 2.5 pump (as shown in the above video) is useless!

    THANKS for the video.

  • Still not sure about the black air knob (even though I have read the comments). Do you have to un-screw it while vacuuming the system? If so, how much? How long should it be left open? The directions that came with the US General 2.5 pump (as shown in the above video) is useless!

    THANKS for the video.

  • hey mike do these gauges work only with us general vacuum pumps? i got exact the same gauges you're using and i tried to hook up my yellow hose to my yellow jacket vacuum pump and the fitting sizes are diferent

  • @luisilloz1 Your yellow jacket pump probably only has a R12 connector. You can buy adapters to convert it though. I have a US General one like the one in this video, and it has both R12 and R134a connectors. The R12 one is smaller. I was glad mine had both, because I just got done converting my old truck back to R12. R134A blew 10 degrees warmer, and that was unacceptable. Buddy had 10 12 pack cases of the little cans he hoarded back in 1994 so sourcing some was not a problem anyways.

  • Thanks a lot for the video. Will the compressor oil come out while the system is being evacuated with this method?

  • @guayacool Only a very small amount of oil will come out during evac. Most of the oil will settle in the compressor , receiver/dryer and other "Low" places in your AC system, as the oil is much heavier than the refrigerant.

  • Comment removed

  • do i need to vacuum high pressure side??? and why?, after vacuum the high pressure do i just recharge the low side??

  • You forgot to note before you turn off the vacuum pump, shut all nozzles off first.

  • hey mike,i have the same gauges and pump.have not used them yet.do you know how to get more instructions on those two units.also,did you flush the system,and how....oh yeah nice video

  • muddiepaws, one vacuum port is the r134a 1/2" acme thread, the other is the r12 style 1/4" flare. some hoses are different and they cover both. great info in the video mikecarter79! just had a total crash course in this to do a job for a friend. thank you!

  • @cnccut79 Thanks the kind & informative feedback. However, the knob I'm talking about is not one of the vacuum lines (1/2" or 1/4"). It is the largest knob on the entire pump. It sits directly over the oil reservoir and has the word "AIR" stamped on it. I wonder what its purpose is, or how it is used, as the pump already has a red colored oil cap on it for adding oil.

  • @muddiepaws , but I would probably not run the pump long at all with that closed as you would probably blow out some internal seal in the pump.

  • @muddiepaws It is cracked open early in vac stage when majority of moisture in system would be present and it allow a small amount of air to enter pump to avoid condensation build up and eventually ruin it.

  • @muddiepaws The "Air" cap is to allow a small amount of air to enter the pump on an initial vac when moisture is most likely present and prevents a condensation build up in pump which would eventually ruin it. I've tried to include a link to another vid but am not able to post the URL for some reason.

  • Thanks for the video. It helped me plenty. I have the same vacuum pump. It's instruction manual is sparse. What does the larger black knob/cap do? How/when is that knob/cap used?

  • @muddiepaws Glad the video helped. The large black plastic screw/knob on the left is where you put in special oil for the vacumm unit. If you are talking about the black knob/cap that is on the same fitting where I have my hose connected to the unit, this is an extra vacumm port.

  • @mikecarter79 Thanks for the feedback. I guess my pump is not identical. My vacuum pump has a smaller "red" capped port for adding oil. The larger black plastic cap has the word "AIR" stamped on it. It is on the far left as seen on your video and is not the yellow vacuum line. Thanks again for this great video.

  • @mikecarter79

    Are you sure that's not exhaust port?? most pumps have a similar cap

  • @mikecarter79 are you sure that's not the exhaust port for the vacuum. most pumps have one with a similar cap

  • Great tutorial, thanks for making.

  • You make a great teacher. The best part is where you say to turn the valve on at the vehicle pressure fittings and show how to turn them. I had hooked it all up and forgot to do that. The vacuum pump showed everything was fine until I did it again with the valves open liked you showed to depress the shraeder valve and then I heard and saw the difference in the vacuum and the gauges. Now I have a real vacuum not just a vacuum in the gauge set hose.

    Thanks a lot! Great tips! Best wishes.

  • Mike.. thanks for your video. quick question.. I have a compressor that is going bad. I got the replacement kit that comes with the drier, o-rings and expansion units. Should I have the ocal shop flush the system and dispose of oil resideus before I do the replacement of the compressor, drier and expansion valve? Once I replace the elements, should I take it back for them to vacume it, place the refrigerant and check for leaks?

    thanks for your advice.

  • Soo When Do You Have To Use The Vaccum???

    Please Let Me Know!

    My 1999 Acura TL is not cooling well.

  • I have a 2000 Nissan Maxima with a non functioning A/C system. The compressor won't turn on, all I hear is fan and all I feel is hot air but I believe that is because there is no freon in the system due to a leak on the condensor so the for safety the system does not turn on. Can I evacuate the system with the pump and try adding 1 or 2 cans of freon along with stop leak and hope for the compressor to turn on or do I have to verify the compressor is working at all.

  • Info like this is very helpful for amateur like me. Many thanks and bless for your time and effort.

  • @ut2usr2 You are very welcome !

  • @mikecarter79 Hey Mike, Is there a 1,2,3 kind of guide to explain this full process of evacuating, recharging and adding the oil to this anywhere?

    I have a 93 chevy 2.8 v-6 pick up that I'm crazy to restore and make the AC work again. I've replaced the hose and accumulator and now I'm tring to understand the basics of prepping the equipment and how it is to be used. Like do I have the engine running and how do I put the brass knob on the pump? It has two ways and a knob that turns please?

  • Very helpful! Thanks!

  • Did your Harbor Freight vacuum pump come with oil in the tank or did you have to buy it. I've got to tackle my a/c this week and I think I'm going to buy your same set-up.

  • @sumrnitz Yes, it comes with a bottle of oil and instructions on how much to put in the pump.

  • Mike, nice video - helped me make sense of how to do this. I am probably going to get the harbor freight gauges. On the harbor freight website, there are reviews of the gauges, in which some people say they had problems with the hoses leaking and/or the pressure readings being way off. Did you experience any problems with your gauges?

  • did you get it discharged at a shop

  • @ezkeyboardkid58 Yes I did. I have a friend in the AC biz who has a refrigerant recovery machine.

  • @ezkeyboardkid58 who cares man, that f@#$%^&*  ( 134a gas is not unsafe to breath, ( a little illegal to let it scape but not unsafe)

  • how do you remove the r134a

  • how do you evacuate the remaining coolant or moisture? Like what do you evac it into? What happens if you just pull vacuum with a recovery unit? will it exit the pumps second fitting?

  • so now you just have the vaccum on and the lines opend

  • Your high side is getting sucked up, lol...and down lol

  • So where is the hose that goes to the container that you are holding the freon in?

  • @stevenmorookian16 When you have finished with the "evacuate" process, you should follow these steps:

    1) close the High(red) and Low(blue) valves AT THE Gauge

    2) disconnect the yellow line FROM THE VACUMM PUMP

    3) connect your R134a or R12 tap fitting to end of yellow hose

    4) Open tap on R134a or R12 so that freon flows

    5) loosen yellow fitting for few seconds at gauge slightly to purge line of outside air/moisture

    6) re-tighten yellow fitting

    7) Engine running, AC on, open low Blue valve

  • @mikecarter79 Thanks for responding. I have the gauges with the 3 colored hoses, just like I see in your video. Do I need a fourth hose so that I can connect the vacuum pump to the freon tank?

  • @stevenmorookian16 No. The yellow hose is used for BOTH the vacumm pump and your freon can. When you are finished evacuating the AC system, you shut OFF the blue and red valves at the gauge, and then remove yellow hose from the vacumm pump. Then attach your freon can tap fitting to the end of the yellow hose. There are only 3 hoses you need, Blue(low pressure side), Red(high pressure side), and yellow(vacumm pump AND Freon or R134a can)

  • @mikecarter79 Oh ok, thanks for the information. I have lots of appliances to suck freon and r134a out of, plus my trucks air conditioning doesn't get cold anymore so I want to evacuate and recharge the freon in that system.

  • Where is your micron gauge to be sure you've vacuumed the system to 250 microns?

  • @raygorsline I don't think an expensive micron gauge is necessary in automotive AC applications. I have never used a micron gauge and I have never had an AC system failure using my methods. The Low side gauge measures vacumm to 30inHg, and that is good enough for me. 30inHg is going to put you in the ballpark of 250 microns.

  • At the end of the evacuation, you have a system that is free of any air or moisture. If you do not evacuate your system prior to charge, it may work for awhile, but the moisture will eventually cause corrosion and other unwanted chemical reactions in your A/C system. This will shorten the operating life of your A/C system.

  • @mikecarter79 I have a ac vacumm pump of 1.5 cfm si this enough to evacuate the system on a suburban or do i need a stronger machine.

  • @27elbebeems 1.5cfm is not ideal but it is adequate. Let it pump for at least 30 minutes. An hour would be better........

  • @mikecarter79 thank a lot i unscruw the fitting under at rear evaporator and the pum runnig and it start suction and now i put it back and is working good

  • Automotive A/C Vacuum Pumps are used to remove air and moisture from an A/C system that has been worked on. If, for example, the A/C system has been repaired(compressor, condensor, evaporator, accummulator,or whatever), this is when evacuation is required. During evacuation, the air is removed from the a/c system and at 28" pounds of vacuum, the moisture begins to boil. The moisture now becomes vapor and is drawn out of the system by the vacuum pump.

  • It is not only necessary, but critical that you evacuate your AC system IF it has been opened to the atmoshere. However, if you are just adding additional R134A Freon to your system, evacuation is not required.

  • i have the vacumm pump and gauges conected and the readings still the same it means i am not getting a good vacumm. nothing atall

  • @27elbebeems What are your readings ?? 0psi ??? I am assuming that your AC system has been bled down to 0psi, ie all refrigerent removed. If you are using quick connect fittings on your gauge set, make sure they are turned full clockwise so they are spressing the shraeder valves. Also, disconnect the yellow from the gauge end, and with the vacumm pump running, make sure that there is "suction" at the end of the yellow line.

  • @mikecarter79 I already check at the end of yellow hose and there is suction including at the end of red and blue when disconected from the low and high port

  • what can i do i have the vacum pum with the gauges conected and i am not getting a vacumm

  • once you vacuum it, did you refill the oil?

  • @061163535 On this particular job, I added approx. 1/2oz oil to be on the safe side. Normally, most of the oil settles in low spots and only a trace amount comes out during the evacuation process.

  • @mikecarter79 i just install a new ac condenser after the accident. should i vacuum the sys.?

  • @061163535 Yes, you need to vacumm in order to remove moisture which entered the system while it was apart. You also need to see how much oil was trapped in old condensor and replace same amount.

  • SO... those cans you buy at Auto Zone etc. really can't do the job properly?

    I'm asking: you have to pull a vacuum before you insert new refrigerant?

    Thanks.

  • @mchar69 If you are just "topping" off a system that is low on refrigerent, then there is no need to do this evacuation. You need to vacumm system when you have opened it up to the outside atmosphere due to any parts that where replaced.

  • @mchar69 Also, make sure that the gauge knobs for the high and low side are full "Open".

  • Does the engine need to be running while the vacuum pump is used? Or should it be off?

  • @deboraheparker05 Engine OFF. 

  • I learned a ton from this video, and am shocked at some of the comments.

    Keep it CIVIL, people!!!

  • @mchar69 Thank you. Nice to hear positive comments.

  • Mike, I have a 97 Chevy silverado and the compressor started leaking maybe 5 years ago. I had it recharged once and it lasted about a year and I recharged it myself using a refrigerant that claimed to stop leaks. That leaked out immediatly. I now intend to replace the compressor, the drier and orfice tube. Is there anything else I should replace? Do you think I would be safe in replacing the parts and evacuating the system without having the system flushed? Thanks for the help.

  • @Pap1010 I have never believed in any of those "AC Stop Leak" additives. You need to locate the leak and replace the faulty component. The Compressor, receiver/dryer and oriface tube are the main components to replace. With taht said, if you have a leaking AC line, or a pinhole in your evaporator or condensor, then that changes the story. Have you isolated where the leak is ?

  • @Pap1010 Flushing the system is one of those "nice to have" deals, but I personally do not think it is necessary UNLESS the compressor has locked up and sent small chunks of aluminum throughout the system. Inspect your old orifice tube for any pieces of metel or aluminum. So, I would recommend a full system flush if you blew out your compressor and you find pieces of aluminum in and around your orifice tube. Otherwise, just pull a vacuum on the system after you replaced all the parts you are rep

  • Give out a little info video and watch people screw up their a/c systems. Nice work mikecarter79. You've got people messing around with refrigerants and systems they really shouldn't be messing with. You the man.

  • @Rueuhy Thanks man !!! You find one piece of info that is incorrect in my video, and please go ahead and post it. Refrigeration is not rocket science like some would believe. It is a simple process of heat transfer in a closed system.

  • Some folks like yourself seem to enjoy ignorance and would rather pay a lot of money getting ripped off by some "qualified technician". Well I have seen quite a few "qualified technicians" in the field of AC, as well as other services, that I wouldn't let touch my stuff.

    I am here to try to help folks. Why don't you do the same, and go help someone do something instead of your mindless criticisms !!

  • @Rueuhy Critcis like you are a dime a dozen.

  • I don't understand how spending $250 dollars on a vacuum pump saved you money. Or spending another $50 or more on gauges. By the time you buy all the equipment you really needed (also a micron gauge and nitrogen tank) to do the job right, you could have paid for at least six visits to a qualified service technician who really knows what they're doing. No matter how many videos a "do-it-yourselfer" watches, it doesn't replace a qualified technician's experience.

  • @Rueuhy Proof of the statement "They walk among us" !!!

  • so what if you have a vehical from 2001 thats a GM and it need freon do we need too evacuate it or can we just add more

  • @walkingfreak No, you do not need to pull a vauum if you are just topping off the system with R134A. However, you may want to inspect the system for any leaks. This video pertains to cars that are completely devoid of refrigerant.

  • @mikecarter79 ahhh how the hell do i tell if its devoid of refrigerant

  • @walkingfreak Hook up a gauge set. Even with the engine and AC system off, there should alays be residual pressure in your system.

  • Checking for leaks when you turn it off,you pointed at the high pressure gauge, what about the low pressure gauge does it have to be below 0? Cuz during the pull is at -1 then I turn off it rises to 0 on the low gauge? But the high gauge is at -1.

  • Is this the 3CFM vacuum pump? How do you determine how long should you draw vac. from system?

  • how is the system evacuated?

    I know we can't dump the old gas to atmosphere.

    so how we can store it.

    thanks for any help

    nice video.

  • what about flushing? what about oil?

  • Hire an A/C Mechanic contractor or auto a/c technician

  • I just changed my compressor and need to buy one of these pumps. Do you have to connect both low and high side or is just one side say low side? I need a pump but

    I am afraid of the Harbor Freight one, you know quality issues. What model number is that pump?

  • Good video Mike, straight and to-the-point. One other viewer asked about oil and I'd like to do that as well. My compressor has developed a leak at the seal so it's time to replace the compressor. I checked the pressures tonight with the HF gauge set. There is absolutely no pressure in the system whatsoever, so no refrigerant either. Assuming that the system will hold a charge (no leaks after evacuating the moisture with the vacuum pump), how do I go about adding oil to the system? Thanks.

  • i have an MTS gauge set for residential- where do i get adapters to connect it to my truck and can a vacuum pump used for residential be used on vehicles?

  • Pretty much at any auto parts store...Pepe Boys, Autozone, Advance Auto...etc.

  • @mikecarter79 Is this the same thing as discharging the a/c system? I have to re place my compressor, and accumulator. How do I discharge the system?????1

  • Is it possible to pull to much vacuum and cause damage to components? Thanks

  • No, a vacumm, also know as reverse-pressure, would never be higher than the 150psi to 200psi you would have on your high side during normal operation. There are no AC vacumm systems designed to ever pull those kinds of "reverse-vacumms"

  • I got a question.

    My car is pretty new. 44k miles. The ac has been running fine. The other day I was at idle and the ac was blowing like warm and not cold. I started driving and after a while it started to get cool again. I thought I needed more freon so I bought some.

    I put the guage on first to see how much I needed but then I found out that I am over-filled. Not dangerously but right on the line between "alert" and "danger".

    Could it be the overfill that makes it sometimes warmer?

  • Too much freon can cause the pressure on the high side of the system to get too high. This can make the high side pressure switch turn off your compressor. There is a similar switch on the low side that will cut off the compressor when pressure is to low, indicating the system needs more freon. I really don't trust those color gauges that come with the re-charge kits. You really need to get a gauge set that measures both the high and low side pressures.

  • Thanks. Could it just be that it is hot out?

    It didnt do this before though.

    And then tonight I got into the car and the AC was running fine.

    If it was a matter of overfilled freon, wouldnt it ALWAYS turn off the compressor and run kind of warm, not just sometimes?

    thanks again man!

  • Yes, in fact it makes perfect sense that it will cut off the compressor more often when ambient temperatures are higher. As the temeratures rise outside, the higher the pressure in your AC system(both high and low pressures will increase since it is a closed system). Since your system is only borderline "overfilled", this would explain why the compressor won't cut out all the time. You should consider removing a small amount of freon to reduce the pressure somewhat. Lessen the chance of a leak

  • that sounds like your engine fans arent comming on properly to keep the pressure down,make sure your fans come on full speed after turning your aircondition on while in park ,if its not check your relays,S/P 1,2 ,but thats what it sounds like to me,,,or you may have what they call an air pocket in your system ,if so youll have to pull freon out and vacuum and put it back in,,,hope this works 4 u

  • Question to Mike Carter. Toward the end of vacuum procedure, you said you need to turn off the vacuum and let it sit for 15 minutes in order to observe any leaks in vacuum pressure. My question is, when you turn off vacuum, do you also close the hi/low lines (close the red & blue knobs)? Or do you leave the lines open?

  • First off, do not close the hi/low flow lines on your gauge. The reason I turn off the vacumm pump and wait 15 minutes is to see if I have a major system leak. So you need to keep these lines open. If you have a major leak somewhere, you will see the gauge needles move from a "vacumm" state(less than 0psi) back to an atmospheric state of equilibrium(or back to 0 psi). Some folks recomend that you wait 24 hours to see if vacumm is maintained, but I think that is a bit excessive.