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batsona
Maryland

join:2004-04-17
Ellicott City, MD
Reviews:
·Vonage
·Verizon FiOS

Checking / Charging the A/C....

I'm thinking all service centers & dealers are set up to garuntee themselves the max. revenue for the min amnt of goods/services supplied. I promise not to make this a rant -- read on!

I'd like to see if my refrigerant level is a bit low just for the sake of making sure the A/C is as cold as it can be. A/C is fairly cold right now however. The local garage was advertizing a 'free AC check', but if the system required refrigerant, they would charge me the $139 for the evacuate/recharge. Really? If the system needs 2oz of refrigerant, I need to pay $139 for that?!

I do appreciate that R12 and R22 is very expensive in this day and age (and maybe even hard to find)? Given that it's not ozone-friendly. I know that there are self-charge kits on the market too.

Is there anyone / any type of service center that will charge me for the refrigerant that they put in, versus charging me to evacuate & refill? That's like junking a new car if the tires need to be pumped up.

nibyak

join:2003-01-28
Strasburg, VA
Just a shade tree mechanic here not an A/C tech. When the gauge-set is hooked up to the system they can tell is if it’s operating within specs. High side high and the low side low (or many additional readings that would indicate issues in the system). If its reading a bit low they can add some refrigerant until its reading within specs, but to my knowledge, there is no way of knowing how much refrigerant is currently in the system. So when they evacuate it, they can measure (by weight) how much came out and when they refill it they will fill it to the amount specified on the sticker under the hood. Im sure you can find some shops that will add a bit of refrigerant until the readings are OK, or you can always go buy a can at Walmart. It shouldn’t be low unless there’s a leak somewhere. When they evacuate the system, they should keep it at a vacuum for a while to determine if it’s leaking.


pmohr
Premium
join:2002-09-22
Maryville, TN
reply to batsona
R12 is not only expensive, but you need a 609 cert to buy it (it's only $20 and an open book test to get the cert, but still).

There's no way to identify exactly how much refrigerant is in the system without recovering (not evacuating) and measuring what you got out of it.

Keep in mind that many shops aren't even set up for R12 anymore, or if they are, it'll cost more for servicing than the standard rates for R134.

Long story short yes, most places will charge you by the amount of refrigerant they put in, but they'll also charge you for the labor and equipment costs associated with recovering, evacuating, and recharging.


cdru
Go Colts
Premium,MVM
join:2003-05-14
Fort Wayne, IN
kudos:7

1 recommendation

reply to batsona
said by batsona:

I'm thinking all service centers & dealers are set up to garuntee themselves the max. revenue for the min amnt of goods/services supplied.

In related news, businesses want to make money. News at 11!

batsona
Maryland

join:2004-04-17
Ellicott City, MD
Reviews:
·Vonage
·Verizon FiOS
reply to batsona
OP here -- No doubt that businesses want to make money, but in my opinion, there's an ethical limit to how much money you can rape from your customers from the least amnt of work. --But luckily that's not the subject at hand

Is there no correlation between the pressure in the system, and the amnt of refrigerant in that system? Wouldn't putting more refrigerant in, increase the pressure, if pressure was low?

I'll admit I'm obviously not an A/C tech - I'm only making logical observations. I'll defer to experts.


aurgathor

join:2002-12-01
Lynnwood, WA
kudos:1
Reviews:
·Frontier Communi..
I'm not an A/C tech either, but since some of the refrigerant should be in liquid phase, while some is gaseous, normally there's no way to tell it for certain based solely on pressure. Especially since pressure will also depend on temperature.
--
Wacky Races 2012!


hortnut
Huh?

join:2005-09-25
PNW
kudos:1
Reviews:
·Comcast
reply to batsona
Poking around some other forums, some give an indication to test a system is to place a thermometer in the vents. Some say a 40 degree difference between output and ambient temp indicates ok.

Others if temp out put is 40F from different outlets, then ok.

With my 134a system, I am at a steady 40F at 90f - 100f outside. Seems to be a crude way to test, but so far works for me over the last 4 years. I am of the belief, if it is not broken why fix it. It is a F150 Supercrew and it cools to a comfortable level in a reasonable time and maintains same.

Thermometers I use are from horticultural uses and fairly accurate.

ymmv


Zatochi
Premium
join:2004-01-17
Bossier City, LA
reply to batsona
I just replaced the AC compressor/clutch assembly on my Toyota Camry. The system was pressure tested and charged with 1.8 lbs of R-134a freon at Firestone. It cost me $123.00. I do not know if that is expensive or not but it was on a Saturday and the outside air temp was 98F. I needed some AC right away.

What ticked me off was that they tried to charge me a $49.95 diagnostic fee on top of that to see why it didn't have freon in it. I already told them that it was empty because the compressor was just replaced. I ended up not having to pay the $49.95.
--
"You gonna pull them pistols.....or whistle Dixie"
Josey Wales


Doctor Olds
I Need A Remedy For What's Ailing Me.
Premium,VIP
join:2001-04-19
1970 442 W30
kudos:18
reply to batsona
said by batsona:

I do appreciate that R12 and R22 is very expensive in this day and age (and maybe even hard to find)? Given that it's not ozone-friendly. I know that there are self-charge kits on the market too.

R12 is Automotive use only and is at EOL*.

R22 is Household use only and is at EOL*.

Last time I saw R12 on sale it was $69 for 14oz in a parts store and you have to be certified to buy it as others have stated already. That means a typical small car A/C system would use roughly 3 of the 14oz cans as it will hold roughly 2 to 2.5 pounds of R12.

Here's a bargain for you:

R12 Refrigerant 12 Sercon 4x14ozs can with oil charge!
»www.ebay.com/itm/R12-Refrigerant···M1062690
Starting bid: US $115.00




Big Lots is selling 14oz cans of R134a for $8 dollars this week and last year it was $4 dollars each can. It has doubled in price at the chain store/closeout store level in under 12 months.
said by batsona:

I know that there are self-charge kits on the market too.

Not for R12 (unless you eBay an old kit) and R22 will not work in your car and will damage it.

HTH

*EOL = End Of Life
--
What’s the point of owning a supercar if you can’t scare yourself stupid from time to time?

batsona
Maryland

join:2004-04-17
Ellicott City, MD
Reviews:
·Vonage
·Verizon FiOS
I guess I was being confusing by talking about R22 and R12. I know my car didn't take R12 because it's so old - I guess I was used to all cars being R22. HOWEVER: I've just verified on the sticker on my radiator, which is barely readable, that I do indeed take R134-A (26oz worth.)

When I had my car at Valvoline (local place just like Jiffy-Lube), they had a heck of a time trying to find the hi-side valve. It was on the bottom of the Condenser, and given where it was, they couldn't hook their gauges to it. Is the gauge / metering device built into the fill-it-yourself cans very accurate?


Doctor Olds
I Need A Remedy For What's Ailing Me.
Premium,VIP
join:2001-04-19
1970 442 W30
kudos:18
said by batsona:

I guess I was being confusing by talking about R22 and R12. I know my car didn't take R12 because it's so old - I guess I was used to all cars being R22.

You have it backwards. R12 is what pre-1995 automobiles used. No autos used R22 ever. It is much older cars that used R12 then it all changed in 1995 (and newer) to passenger cars and light trucks exclusively using R134a from the factory.

said by batsona:

When I had my car at Valvoline (local place just like Jiffy-Lube), they had a heck of a time trying to find the hi-side valve. It was on the bottom of the Condenser, and given where it was, they couldn't hook their gauges to it.

Why not? Gauges come with long enough hoses to reach the entire engine compartment front to back. There is something fishy about that excuse.
said by batsona:

Is the gauge / metering device built into the fill-it-yourself cans very accurate?

Not at all. I would not trust one of those throw away gauges on a freon can.
--
What’s the point of owning a supercar if you can’t scare yourself stupid from time to time?

robbin
Premium,MVM
join:2000-09-21
Leander, TX
kudos:1
reply to batsona
What do you see in the sight glass? Are the bubbles?

sailor
Premium
join:2003-10-21
Long Island
kudos:6
reply to batsona
I still have some cans of R12 laying around from the days when I was big into collecting older model vehicles....for example, both my 81 and 86 Lincoln Town Cars had original R12 systems.


south1178
Premium
join:2001-12-17
Cleveland, OH
reply to batsona
You could try converting your R12 system to 134a. This is what I plan on doing to my 86 Firebird.


jlhugh
Premium
join:2001-09-07
Cedar Creek, TX
reply to batsona
and to make it even more confusing there is a new refrigerant coming out HFO-1234yf. if your system is low there is a leak somewhere. it needs to be evacuated and pressure tested for leaks or you will be back to add more R134a in the future. you could right now since it already has pressure in it. get you a squirt bottle with soapy water and spray all the a/c connections looking for bubbles. spray the whole condenser down as it might have a hole in the middle somewhere. spray the pressure switches and the schrader valves also (the ports). even spray the compressor behind the pully. there is a seal there that leaks.
--
~Team Discovery ~ Project Hope ~

scross

join:2002-09-13
Cordova, TN
reply to batsona
Let's assume that we really are talking about R134a here (R12 and R22 are different animals, requiring EPA licenses to work with). EVERY factory manual I've seen says to follow the evacuate/recharge procedure - which makes perfect sense if you've had a sudden loss of refrigerant (implying a serious leak and possible moisture contamination of the system), and also makes service techs happy because it's fairly easy money. But, EVERY mobile AC system also leaks a bit by nature (just like tires do), and very often what you're dealing with is just normal leak-down over time (R134a is supposed to be a bit worse in this regard than R12 was), which doesn't require any heroic efforts unless maybe the system has completely lost its charge.

So, the short answer to your question is just to go buy one of those R134a self-recharge kits, read the instructions carefully and then follow those instructions carefully. You may not end up with a "perfectly" charged system, but if you do things right your system will cool much better than it does now. But you may also find (as I have) that what should be an easy-to-reach, DIY-friendly charging port has been INTENTIONALLY located in an area which makes it difficult to work with for the DIY crowd.

batsona
Maryland

join:2004-04-17
Ellicott City, MD
Reviews:
·Vonage
·Verizon FiOS
OP here: Thanks for all the discussion -- and sorry for again stating confusing things. Had I used my head for 4.5 more seconds, I would have known that R22 was always for residential A/C, and was never used in cars.

Otherwise, I know I don't have a huge leak, since my A/C is still fairly cold. This is just me thinking, "can it be any colder" (meaning= am I at my optimal charge..?)

as far as fitting hoses on a concealed hi-side valve -- I didn't see what apparatus they were using; I didn't see how long their hoses were.

scross

join:2002-09-13
Cordova, TN
reply to batsona
Well, to confuse things a bit further, while it is true (AFAIK) that R22 was never used for the automotive portion of AC systems, for things like mobile homes it might very well have still been used for the AC sitting up on top, and the refrigerator, and so on; but I could be wrong. If true, though, then for someone to be fully qualified to work on all of this stuff they would need different licenses, different refrigerants, different equipment, and so on.

Now, concerning R134a, as a consumer you would never work with the high-pressure side; only the low-pressure side. And by law (and unlike older refrigerants) these two fittings are different sizes and can't be physically confused (IIRC the low-pressure side uses a larger fitting than the high-pressure side; it may also be a different color and have different markings). Consumer equipment that you might find in Walmart or Autozone or wherever is restricted to using only the larger, low-pressure fitting. Which makes it all the more infuriating that they would (as they have on many cars) make the high-pressure, technician-only fitting very easily accessible (on top, right out there in the open), while the low-pressure, consumer fitting is buried down low on the firewall - hard to see, hard to get to, and quite physically uncomfortable to access. AFAIK there is no sane reason why this fitting shouldn't be right out in the open, just like the other fitting.

HarryH3
Premium
join:2005-02-21
kudos:3
Reviews:
·Suddenlink
reply to south1178
said by south1178:

You could try converting your R12 system to 134a. This is what I plan on doing to my 86 Firebird.

If your system doesn't leak, stay with R12. Converted systems don't cool nearly as well, as they weren't designed with R134a in mind.

batsona
Maryland

join:2004-04-17
Ellicott City, MD
reply to robbin
There's a sight glass? I haven't see one of those since my mother's '73 Chevy Impala.... where would it be on the focus?


Cho Baka
Premium,MVM
join:2000-11-23
there
kudos:2
Just a wild guess, but perhaps on the high side piping between the condenser and evaporator.
--
The talented hawk speaks French.