My a/c went out this winter and it seemed like it was leaking and leaking through the vents when i was using it one day. i was preetty mad but hadnt fixed it since. i want to fix it now so i can have it. anyway im scare dthat there is a leak somewhere in it and i kind of know the procedure to check for it wihle recharging it.

do i just connect a can of refrigerant and oil to the low pressure side and fill? do i have to have teh a/c compressor on while filling? reason i ask this question is because i just took my bros car in 96 monte carlo z34 and the guy used one of the a/c machines and used it to fill it and i asked him if we needed the a/c comproessor on and he said know. the machine vaccuumed all the air out and filled it with the car off. he said there was a leak and so he added 1 oz or dye to it. he also said that when it starts to not cool anymore then to bring it back so he can use a blacklight on it to find the leak. i hope my leak isnt bad either as i hope my bros isnt. it was quite expensive, total came to 123 because parts were 70 bucks 2 and quarter pound of refrigerant and the dye cost 25 bucks damn. and the to use the machine was 50 bucks. anyway i dont want to pay anyone to do it i want to do it myself. i kn now i can get those refrigerant refill kits at walmart or advance for like 30 bucks or so is that everything i kneed. do i have to suck all the air out with a vaccuum? how would i do that? where do i get the red dye from to check for leaks? and how do i find the leak and what would i have to fix/replace? i hope its nothing major. i want to refill it. how do i jump the a/c compreessor to turn it on? i probably have no refrigerant at all right now in it so i need to jump my compressor right? how do i do that? how much oil do i add in it or do i just buy the cans with oiil and refrigerant mixed in? i hope you guys can help me. sorry for the long post thanks. let me know asap.

 

just wanted to update. i ran a serach on this site and found a few answers but i still will need to try it. i do think i have a leak and i hope its not serious and expensive to fix. i will be going to get the red dye as well as a reccharge kit soon. any ideas please let me know thanks a lot.

 

If it is leaking into the vents, then your evaportator probably has a leak. I would charge it up and see how long it lasts. If it lasts for a month or two, I would just keep some 134a on hand and top it off every once in a while. If it leaks down in less than a week or so than you have a bad leak and will have to get it repaired.

If you do it yourself, start the car, turn a/c on max and once you get enough charge in it the compressor will kick on. Use the gauge that comes in the kit, dont over fill. Hook up to the low side port and fill with the can right side up.

good luck

 

sweet man. thanks for answering some of my questions. it has been very ehlpful. is the evaporater the same as the drier also? yea i will be hopeflully charging it up soon. i hope it lasts a few months b4 it leasks so forth and like you said i could just fill it up when its a lil low. so the compressor will kick on when it gets enough charge in it? i dont have to jump it lik emost people have said to do. i heard taht if u jump it u can let it run long without freon in it otherwise it could mess up the compressor. yea i know where the low side port is so i just have to fill it. will 2 12 oz. cans do it or 3? it holds 2 lbs i think so thats 32 oz? 2 and a half cans? will that work? im pretty sure i hafve no freon in the system at all cuz the compressor doesnt kick on or anything. thanks man. u have been helpful. let me kno won the evaporater. is that the silver canistor the drier/accumulator right? 40 bucks i read somehwere NEW?? from the dealer? thanks man.

 

the dryer and evaporator are not the same thing. The silver canister under the hood is not the evaporator. Do not jump the compressor, just add the first can and it should kick on. Use the gauge and check the level after each can. You may still have some in the system, so just keep an eye on it. When I am charging, I have the fan on high and have a thermometer in the vent. You should be able to get between 40* and 45* when fully charged. Anything under 50* should be ok though. Dont go just by temp though, use the gauge.

 

then where is the evaporator? is it expensive? easy to replace? im glad i dont have to jump the compressor because it can cause damage i have read. i hope its not leaking and was just low but im kind of worried that it is leaking. i will soon find out. how many cans does it usually take? 2? 3? im talking of the 12 oz. cans. or how many lbs? 2? if its 2 lbs thats 32 oz. so 2 and 3/4 cans of 12 oz? thanks man. i hope its all good.

 

ok. the evap core is cased in that black box on the pass side firewall. you will see the 2 ac lines going into it..

look under the hood for a sticker on AC charge specs. shold say this system will hold x pounds.. usualy it will be 2 pounds. this is a compleatly empty chagre. use this formula


1 pound = 16 ounces

tehre are usualy 12 ounces in a can

so take 2 pounds (or how ever much it holds) X 16 ounces = 32 ounces

32 ounces divided by 12 = 2.6666 cans.


so a full charge means almost 3 cans.



now.. to reiderate some..

NEVER EVER EVER jump the pressure switch unless you have a REAL set of manifold gauges to see whats going on or your asking for trouble.

to fill the system you hook into the low side (larger of the 2, also called the liquid or suction side)

you can add about 1 can ish with everything off. This will get you enough in there to alow the compressor to cycle as you start it up and will also tell you if you have a substancial leak. the reason that he could add a full charge with it off is cause he was using a 30 pound large can. there is more pressure in the can then in the car so it will add. as where there is less pressure in that little 12 ounce can then there is in the car (think of it as adding air to a tire with a small air tank. when you have 30 pounds in the tank and you fill a flat tire it goes in fast. but when you have 30 poounds in the tank and 30 pounds in the tire it will not add more air. same idea


then. with the car running, the AC on MAX and the fan on high you can start to add the rest of the freon. after the second can you should see that teh compressor is runing all the times and the fans are starting to come on..

if your starting compleatly epmty just fill using the formula above. this will insure a compleate charge. now, if you are just adding some be carefull.. you could add too much. remember, pressure changes with temp. so if it;s cold out pressure will be lower, if it;s hot pressure will be higher. so remember that when your adding. usualy about 45 PSI on the low side is where you wanna be.


one way that you can check for leaks at home.. a spray bottle with some dish soap. spray it on the lines, compressor, fittings, condensor etc etc etc and watch for bubbles.

 

thanks man! that was so helpful. you pretty much answered all my questions. do you think i have a leak from the symptoms i said. i do have one thing that i rmemeber now. before my a/c quit working or what i believed was leaking out my vents. i did recognize that the compreessor would cylcle on and off quickly instead of staying on all the time while the a/c was actually on. i hope that it was just low and got to the point that it was too low of pressure to kick the compressor back on. i shouldnt have any moisture or air in it since i never opened it up. i will be getting the a/c cans tomorrow as well as try to find a good presssure guage so i can keep an eye on the pressure. if i follow your directions are you positive it will work this way? have you done this way urself? it seems pretty easy to do as you said and hopefully i can add 1can in before starting it and turning on the a/c so then i can add the rest to fill it up. i hope it will work right and i have no leaks. thanks again! let me know if you have any other suggestions or believe i do have a leak or just low on freon thanks.

 

I rarely use a mechine to charge a car. I usualy do it with a good set of manifold gauges.

Yeah if it leaked out once then filling it just means that it will leak out again. I don;t see how it's coming out your vents tho. if it was that much of a leak that you would see things coing out the vent it would all leak out in a mater of minutes....

 

where can i get a good set of manifold guages and how much do they cost? now that i think about it i dont think it did leak out the vents like i said. i think i remember the a/c coming on and off like it would blow cold air and then back to cool air without a/c then cold air again and eventually it quit working. what i think happened was it got low on freon and the compressor was cycling on and off thus the cold air than normal air cold air then normal air and so forth. so i think i just need it recharged hopefully. anyways heres and update.

i went to walmart tonight and bought the r134a retrofit kit or recharge kit. it is the one with 3 cans and the gauge and the retrofit adapters to convert your existing r12 to r134a. anyway it comes with 3 cans of 15 oz. refrigerant, oil, and leak sealer. like 13 oz of refrigerant and 2 oz of oil in each can. it also comes with the guage. i have a few questions. does anyone know the exact amount the a/c system holds? im thinking around two lbs. like you said. i should have enough 45 oz is 3 lbs. 1 oz. is the guage accurate? when i go to fill it tomorrow how do i use the gauge to check the pressure. do i just hook up the guage without a can of refrigerant and check it? i would think all the refrigerant in would come out the other end. i think i need to have it hooked up to a can to check it i just cant check it without something on the other end of the guage. at walmart tonight i saw an a/c pressure guage that was blue and had the guage on it. u just hook it up an dit reads the pressure. im thinking i can use the gauge that came with the kit the same way hopefully. anyways i will be doing this tomorrow and hopefully all goes well. herres what im going to do, my procedure. correct me if im wrong anyone.

from what you guys have said this is what i am supposed to do.

keep car off nothing running.

add 1 can of refrigerant to the low pressure side of a/c system, i know where its at.

check pressure after adding one can.

turn car on, set a/c on max and fan on setting 4 or highest setting

i should hear the compressor turn on at least because of the refrigerant in there. it might turn on and off but thats normal cuz not enough refrigerant yet.

add another can and check the pressure.

tha towuld be 30 oz almost 2lbs.

then the compressor should stay constantly on and hopefully a/c is blowing cold air.

add until pressur reading on gauge is 45 psi???? in the instructions it came with the guage says 45 psi is filled and anything above is over filling. i will be following these directios too somewhat.. iit also says to turn the can upside down after shaking. do i turn it upside down or can i have it right side up? i thought u just have to have it right side up.

anywayh i will be doing this tom. hopefully no lkeaks and all goes well..

sorry for the long post. let me know what you guys think and if anyone knows the exact amount of a/c in ounces or pounds it holds thanks.

 

Sticker under the hood will tell you[R134a] 2 lb total for my 94.. yours is probably the same amount..
I got a pretty nice full set of R134 guages from Harbor Freight for about 50 bux..
See:
http://www.harborfreight.com/cpi/cta...temnumber=2435
Pretty nice, all it didn't have was the fitting to pierce the cans with[which you already have?]The one you have probably will screw on there, mine did]Has the quick connect fittings for high and low side etc..you hook the center line to the can and use the valves to put it in, also to check the pressures of high[red] and low [blue] side..well worth 50 bux..
The actual final pressure you need is based on ambient temperature and humidity.. [higher temp humidity = higher pressures..]
If you put 2 12 oz cans in, that totals 24 ounces[1-1/3 lb] not 2 lb
I put the cans in a basin of hot water when I do them.. [that emptys the can better..] tho it should be OK without doing that..

 

yes. that harbor frieght link is a proper set of manifold gauges. it;s not the best but it's a hell of a lot better then that non acurate gauge from the wal mark kit.

Look on the sticker under the hood to make sure of the full charge specs. if you get that manifold gauge hook it all up. blue to the low side red to the high side. the heads pull back like a qucik release cupler and then presses down on the port, then you screw the top down to tighten it.

Take a pressure reading with the car off. unless you see 0 on both gauges you will just need to charge untill your in the right pressure.

now... your going to need a can tap valve if you get that gauge set. it is what screws onto the freon can and the gauges and will poke a hole on the top of the can. so make sure that you get one of them too.

I would Honestly just add foreon and maybe a 2 ounce oil charge but you don;t need to stick anyuthing else in there. it sounds like your gonna be about a can low. so just stat the car and stat adding a little at a time.. the can hooks into the middle hose. make sure both valves are closed.. peirce the can and hold it upside down. then open the blue, low side valve and freon will start entering. while your filling watch the high side pressure. if it gets near 200 stop and weight.. charge it a little at a time till your around 230-245 ish high side and then stop. make sure that your low side is around 40 PSI and your done.

 

thanks for both or your replies. very helpful. those a/c guags are the exact same ones that the a/c machine had in the shop. only he didnt hook up the high pressure side. he just used the low pressure side to hook it up. i probably wont be spending the 50 to get these guages even though i have seen them b4 at harbor. excellent tool store imo. i buy a lot of tools from there.

mrmthds94z- the cans i have are 15 oz cans and they have 12 oz of refrigerant and 3 oz o foil in it. is that too much oil? i had planned on adding around 2 cans but hcekcint the pressure so i know how much will be in. 2 full cans of 15 oz would be 30 oz. almost 32 oz of refrigerant almost 2 lbs. i will try this and hopefully that will be neough. i do have the tap valve, it came with the kit i bought last night, and that tap valve connects to this inline guage. i kno wits not like those good a/c manifold gauges but i hope it will work this time and be somewhat accuratre. acccurate enought to work. that would be great for me.


hbhracing- i probalby wont get the guages like i said up in this post cuz i will be doing this today. earlier in a few of your posts in this thread u told me to keep the car off, add one can then start and check pressure and add accordingly until full. now you say that you think im a can low and just start the car add it and check pressure and then fill accordingly till full. now that you have said this process. i think ia m going to start the car then add and check pressure to fill it. hope this is all i have to do and all goes well. let me know guys i will be doing this in a sec thanks.

 

if you hook up the gagae with the car off and it;s got some in it then charge it with the car on.

I would not add more then 2 ounces of oil. 3 at the most. the system still has a full oil charge in it alreadys and unless the compressor is making noise you don;t need any.

 

ok i will check it with the car off first. well each can has 3 oz and thats what it came with? its 15 oz 12 oz or refrigerant 3 oz of oil in each acan. do i have to buy just a reg can of refrigerant instead? will too much oil hurt it? cause any prooblems? thanks