[FAQ] How-To: Charge your A/C air conditioner conditioning system at home

[Frozen E]

Originally Posted by drumminforev I also disagree with your first sentense. Why would it blow the oil out. Yes, SOME would come out, but not nearly all. That would mean that the shops would be sucking all the oil right out to. But that is not what happens. If i am wrong, do correct me. You ARE wrong in this case. The internals of a vacuum pump and a recovery machine compressor are like night and day. Vacuum pumps are designed to pull a system that's at atmospheric pressure down into a vacuum. The internals are not designed to have positive pressure going into them and keep the oil in the sump. Recovery machines actually use hermetic compressors that could be compared to the one found in your house fridge, ice machine, or window AC. They're deigned to have upwards of 100 psi on the suction side and be fine. If you ever get a chance to cut the top off a small refrigerator compressor I suggest you do it. Pretty cool actually. Their internals won't let the pressure on the suction side push the oil out of the crank case. Nearly impossible.

This ad is not displayed to registered or logged-in members. Register your free account today and become a member on Honda-Tech!

[methos713]

nice write-up...i have a couple of questions though...but I'll IM you about it when I'm at home.

[astrosurfer]

well to be honest i had no idea about evacuating before last night when i read your erm "column" so to say
i researched as to why i still had no cold air.
and today i find that the air is a little colder but not much although noticable.still not cold tho
i will have to find a way to evac it and hit u back as money is tight right now for the luxury of cold air. but i will research cost
thanx for the speedy reply bro
appreciated

respex

also a little p.s.
you didn't comment on whether you thought i had no leaks coz of my pressure being high, which i assume to be because of the air in the system
i had like 60 psi on the low.i will retest tomorrow ( saturday) and check periodically
for pressure loss

but thanx again

[Dwight Schrute]

i was at a local store today and i saw they had their ac stuff 40% off, so i picked up a r134a retro kit for 25bucks. it comes with 3 bottles of r134a and a bottle of oil and all the fitings. my car is currently r12 and blows slightly cold air. i was planning on buying some r12 or r12 equivalent online until i came across this deal. would i be better off using the retrofit or just getting some r12/r12 equivalent?

btw, i plan on vacuuming out my system with the pump and following the guide here. im also going to see about getting a shop to recover my old refrigerant and check for leaks if it isn't too much money.


Modified by drewthomas14 at 11:43 PM 8/4/2006

[drumminforev]

Originally Posted by astrosurfer

well to be honest i had no idea about evacuating before last night when i read your erm "column" so to say
i researched as to why i still had no cold air.
and today i find that the air is a little colder but not much although noticable.still not cold tho
i will have to find a way to evac it and hit u back as money is tight right now for the luxury of cold air. but i will research cost
thanx for the speedy reply bro
appreciated

respex

also a little p.s.
you didn't comment on whether you thought i had no leaks coz of my pressure being high, which i assume to be because of the air in the system
i had like 60 psi on the low.i will retest tomorrow ( saturday) and check periodically
for pressure loss

but thanx again

The high pressure is definately from air/moisture. The only way to tell if you have a leak is to put the gauges back on and check if the pressure has dropped any since you originally charged. Or use an electronic leak detector like I was advertising.

Originally Posted by drewthomas14

i was at a local store today and i saw they had their ac stuff 40% off, so i picked up a r134a retro kit for 25bucks. it comes with 3 bottles of r134a and a bottle of oil and all the fitings. my car is currently r12 and blows slightly cold air. i was planning on buying some r12 or r12 equivalent online until i came across this deal. would i be better off using the retrofit or just getting some r12/r12 equivalent?

btw, i plan on vacuuming out my system with the pump and following the guide here. im also going to see about getting a shop to recover my old refrigerant and check for leaks if it isn't too much money.


Modified by drewthomas14 at 11:43 PM 8/4/2006

r12 and freeze 12 work great. I am a fan on NOT retrofitting. Freeze 12 can be picked up for like 9 dollars a can at http://www.freeze12.com/ through one of their distributors. I believe napa even carrys it.

Retrofit will work, if done properly, but with potential of damage to your compressor since it was not designed to handle pressures upwards of 50psi low and 200psi high.

Originally Posted by IslandSi

You ARE wrong in this case. The internals of a vacuum pump and a recovery machine compressor are like night and day. Vacuum pumps are designed to pull a system that's at atmospheric pressure down into a vacuum. The internals are not designed to have positive pressure going into them and keep the oil in the sump.

Recovery machines actually use hermetic compressors that could be compared to the one found in your house fridge, ice machine, or window AC. They're deigned to have upwards of 100 psi on the suction side and be fine. If you ever get a chance to cut the top off a small refrigerator compressor I suggest you do it. Pretty cool actually. Their internals won't let the pressure on the suction side push the oil out of the crank case. Nearly impossible.

Thats interesting info. Glad you told me.

[Buggin]

1st - Mad props for this how to.

Car - 1995 Del Sol Si
Symptoms - A/C just stopped blowing cold air one day. The compressor kicked on and the system still had a good charge.
Diagnosis - Hooked up manifold set. Saw that there was good pressure on low side but high side read same as low (40psi). Removed plug from pressure switch and jumpered the pins to ensure the switch was working (check good). Removed plug to a/c compressor and verified 12v was present (yes). Replaced Compressor, expansion valve and drier.

I picked up a gauge set for $29 at Harbour Freight (yes, they will match on-line and catalog prices in the store if you print it out). They seem to have all the readings that the more expensive gauges at auto parts places had. Also, if you have an air compressor that will supply 90psi continuously, you can pick up this handy "pump" for $10 there also. I had no problem pumping down to -28 with it.



If you have an O'Reilly auto parts near you, they were cheaper than Autozone for parts.
Expansion valve - $33 [Murray part #39000] (they have the wrong part# listed for the Del Sol)
Drier - $20 [Murray part #33588]
Compressor - $260 (with military discount and some bargining)

One thing, the expansion valve is on the evaporator inside the car behind the glovebox. You will need to remove the battery also to disconnect the lines going though the firewall to it. Not hard to do, I just couldn't locate it at first.

Once again, thanks for walking us though this!

[drumminforev]

Pure pro dude, pure proness. Pics own too.

I am deff gonna check orilieys cuz autozone wanted 60 and it didnt even fit, for the drier.

And on a side note....does anyone have experience with a 1999 jetta 2.0. I got a customer who needs the compressor replaced, so I'm lookin for any advice on how its layed out and what to watch out for.

[Buggin]

Jetta info

As I'm a V-Dub person. The Del Sol is my girls... I can provide an illustrated parts breakdown from the ETKA disk. Other than that, I haven't had to tackle the A/C on my VW yet... I do know that the pressure switch is known to go bad. Also, look at the fuse panel on top of the battery box (if it's set up like my 1.8t), The fuse and wiring have melted on MANY VW's that I've seen , causing intermittant, then no A/C. So be sure to check for power at the compressor.

Since the pics are kinda big and not really related to this site, I'll just put the links up:

http://www.wrhhh.com/misc/jetta-image.jpg
http://www.wrhhh.com/misc/jetta-ipb.jpg

[drumminforev]

You own dude. Thanks!

[imadigitalgod]

Originally Posted by Buggin

I picked up a gauge set for $29 at Harbour Freight (yes, they will match on-line and catalog prices in the store if you print it out).

crap! i should have done that first. They wanted $62 at the local HF store...but i didnt think of price matching. i still dont see how they can sell the whole a/c gauge set with the service port converters for $29 tho. I mean the converters alone cost $25 that i have seen on the net. So thats like paying an extra $4 for the gauge set and the hoses...sounds like a good deal to me! I got it off of their website. $39 including shipping so not TOO bad

Originally Posted by Buggin

Also, if you have an air compressor that will supply 90psi continuously, you can pick up this handy "pump" for $10 there also.

Im sure it will work, its just for my taste, it wont pull a deep enough vacuum

I converted the micron rating of that air compressor pump and it will pull down to a max of .7 psi. my vacuum pump that has a 200 micron vacuum rating is converted and will pull a vacuum down to .004psi. like i said it seemed like it worked 100% alright for you...i just am one of those ppl that get the best of the best, u know?

But still " " to u fixing ur a/c.

[spoonwheelsSD]

sweet write up!

[97civicdx]

Freeze-12 is a blend refrigerant. It is a mix of r-134a and another chemical. Although its properties are excellent for r12 cars, most shops wont touch it or use it in their conversions. Although you can buy it online, good luck servicing your a/c once its inside.

[Frozen E]

Originally Posted by 97civicdx

Freeze-12 is a blend refrigerant. It is a mix of r-134a and another chemical. Although its properties are excellent for r12 cars, most shops wont touch it or use it in their conversions. Although you can buy it online, good luck servicing your a/c once its inside.

Yep, blends suck. Mainly because once you have a leak you can't just "top it off". You have to pull everything out and start with a fresh charge.

[imadigitalgod]

Im looking up what exactly Freze 12 is...can it really be used in a r-12 system that is totally empty...or if its been retrofitted to 134a? im not sure which one. I looked at my friends 93 blazer and it seems to have the fittings for 134a(i have an a/c gauges set that came with the high/low side converters and they both fit on the service ports.

if it can be used in either r134a or r12 systems and i dont know what it is, would this be the best option 2 use Freze 12?


Modified by imadigitalgod at 1:02 AM 8/9/2006

[jdmOPTION2]

hell yeah. nice how to

[astrosurfer]

hey dude
nice post
tho when i looked @ harborfreight online the pump is $16.99 and the gauges are as you say $29.99
so you say they honor the online price, gonna get me some of this stuff
doesn't get cheaper than that eh?
is that a pump you need to hook up to an air supply?
been reading that they are not good enough
but if you say it worked then i guess i gotta try it
tho i found a pump for a little over $100 online that plugs in.
sadly i don't have an air supply
any ideas about pressure requirements etc?
thanx again dude


and to you drummin'
checked the pressure again and i had none
so i guess i got a good leak going on
i guess an o-ring set is in order
also when i hooked up the r-134a gauge on the can i noticed the compressor kick in when i gave it a few squirts to see if it was dead, previously while running the motor today it would not kick at all.
does that mean it is working or not
any ideas

[drumminforev]

Originally Posted by astrosurfer

hey dude
nice post
tho when i looked @ harborfreight online the pump is $16.99 and the gauges are as you say $29.99
so you say they honor the online price, gonna get me some of this stuff
doesn't get cheaper than that eh?
is that a pump you need to hook up to an air supply?
been reading that they are not good enough
but if you say it worked then i guess i gotta try it
tho i found a pump for a little over $100 online that plugs in.
sadly i don't have an air supply
any ideas about pressure requirements etc?
thanx again dude


and to you drummin'
checked the pressure again and i had none
so i guess i got a good leak going on
i guess an o-ring set is in order
also when i hooked up the r-134a gauge on the can i noticed the compressor kick in when i gave it a few squirts to see if it was dead, previously while running the motor today it would not kick at all.
does that mean it is working or not
any ideas

Your compressor wont turn on if the system is empty. So by giving it a few squirts, you created enough pressure to deactivate the lowpressure cutoff switch, which turned it back on.

Those little 10 dollar "pumps" suck. They suck dick. You need to have something like a CONSTANT 90psi at 2.5cfm, which is a lot of air flow. You will need at least a 1-2hp motor for that. And for that price, its worth it to buy the REAL deal for only 100-150 bucks online. Or you could just rent it from me and get 95% of your money back when done.

Originally Posted by IslandSi

Yep, blends suck. Mainly because once you have a leak you can't just "top it off". You have to pull everything out and start with a fresh charge.

Good point. This is because it might not have leaked out equally, so topping off could cause an uneven blend. But, I wonder if this would even matter. It probably wouldnt make a difference.

Originally Posted by 97civicdx

Freeze-12 is a blend refrigerant. It is a mix of r-134a and another chemical. Although its properties are excellent for r12 cars, most shops wont touch it or use it in their conversions. Although you can buy it online, good luck servicing your a/c once its inside.

Why "good luck servicing your ac"?

[Dwight Schrute]

also want to know why freze 12 is so bad. i dont really feel like buying new r12 since i can't "legally" get it. i plan on draining my current r12 and putting freeze 12 in. i just dont want to do it if there will be problems

[drumminforev]

Originally Posted by drewthomas14

also want to know why freze 12 is so bad. i dont really feel like buying new r12 since i can't "legally" get it. i plan on draining my current r12 and putting freeze 12 in. i just dont want to do it if there will be problems

What the expletive did you just say? I HOPE you have a grand ass reason for draining r12 and putting freeze 12 in. If you are just doing it because you think its a smart idea....don't.

[Dwight Schrute]

i have to because i need a recharge. my system is r12. freeze 12 is a r12 replacement , and i can't buy r12 legally , so it's my only other option besides converting to r134a.

[RNPoo7]

Will a 92-93 Integra GSR compressor (B17) fit on a 00 GSR (B18C)??

[Frozen E]

Originally Posted by drumminforev

Good point. This is because it might not have leaked out equally, so topping off could cause an uneven blend. But, I wonder if this would even matter. It probably wouldnt make a difference.

In an automotive application it really doesn't matter.
Hell, we used R22 one time in the desert in one of the trucks. Worked "decently".

[chrisw85]

I just picked up my manofold set and checked my system. 94 civic with 134a. after 10 minutes to stablelize pressure at about 1500rpm, i let it idle (about 700rpm) and took these readings:
vent temp: approx 58-60
high:approx 220
low:approx 40
ambient temp: approx 90

i think my low side valve core is leaking cause when i took off the quick coupler it starting bubbling where as the high side didn't. Thank goodness i have rubber seals in the caps.

a recovery, dryer replace, and vacumm and recharge are in order.

[Frozen E]

Originally Posted by chrisw85

i think my low side valve core is leaking cause when i took off the quick coupler it starting bubbling where as the high side didn't. Thank goodness i have rubber seals in the caps.

Mix up some dish soap and water and leak check all your fittings by pouring the mix on 'em. Find your leak or else it'll an ongoing and never ending battle .

[chrisw85]

it is the low side valve core. i bought the repair kit at autzone to try and tighten it but it is already tight as is, and since the system is charged i cant just change it out. I'll wait until i get a chance to get the 134a recovered and then i'm going to buy a vacuum pump, new dryer, and the orings and all that stuff.