All,

Have any of you done a recharge on your A/C unit? Mine seem to have
run out and needs to be charged. If you've done it, do you recommend
using one of the kits available at an auto-part store (Murray's,
AutoZone, etc.) or have it done by a pro? I've been told the kits are
pretty easy to use so I would like to learn to do it myself. Thanks
for any help.

- Thee Chicago Wolf

To do it right, you need to start from scratch, which means you need a good
set of gauges and know how to use them. You also need a vacuum pump to hook
up to the system, which will cost you about $400 or so. You really do need
to know the procedure so get a shop manual for the car. If you do it wrong,
and open up the high pressure side to the can of freon, you're dead! It's
really not that hard but you just need to know the steps and precautions.


"Thee Chicago Wolf" <.@.> wrote in message
news:5tbhd2te93oblpfuhksh6ebhrk66en8vb4@4ax.com...
> All,
>
> Have any of you done a recharge on your A/C unit? Mine seem to have
> run out and needs to be charged. If you've done it, do you recommend
> using one of the kits available at an auto-part store (Murray's,
> AutoZone, etc.) or have it done by a pro? I've been told the kits are
> pretty easy to use so I would like to learn to do it myself. Thanks
> for any help.
>
> - Thee Chicago Wolf

"Tom" <tjwitman@bellsouth.net> wrote in
news:5oRCg.4515$ID1.1966@bignews2.bellsouth.net:

> To do it right, you need to start from scratch, which means you need a
> good set of gauges and know how to use them. You also need a vacuum
> pump to hook up to the system, which will cost you about $400 or so.
> You really do need to know the procedure so get a shop manual for the
> car. If you do it wrong, and open up the high pressure side to the
> can of freon, you're dead! It's really not that hard but you just
> need to know the steps and precautions.

Sorry, but you don't need a vacuum pump. If you have good gauges, hooked
up to the right ports, know the ambient air temp., and how much charge the
system is supposed to have, you can fill the system properly without a
problem.

Eric

[original post is likely clipped to save bandwidth]
On Fri, 11 Aug 2006 14:07:16 GMT, "Eric G."
<NgOrSePeAnM99@Zoptonline.Znet> wrote:

>"Tom" <tjwitman@bellsouth.net> wrote in
>news:5oRCg.4515$ID1.1966@bignews2.bellsouth.net :
>
>> To do it right, you need to start from scratch, which means you need a
>> good set of gauges and know how to use them. You also need a vacuum
>> pump to hook up to the system, which will cost you about $400 or so.
>> You really do need to know the procedure so get a shop manual for the
>> car. If you do it wrong, and open up the high pressure side to the
>> can of freon, you're dead! It's really not that hard but you just
>> need to know the steps and precautions.
>
>Sorry, but you don't need a vacuum pump. If you have good gauges, hooked
>up to the right ports, know the ambient air temp., and how much charge the
>system is supposed to have, you can fill the system properly without a
>problem.
>
>Eric

You need a good sensitive refrigerant scale. Virtually all automotive AC
systems are charged by weight, not pressure/temperature.

gerry

--

Personal home page - http://gogood.com

gerry misspelled in my email address to confuse robots

gerry <gerrrry__net@gogood.com> wrote in
news:ds8pd25orts9h32ivp6t4janjjmhua6cch@4ax.com:

> [original post is likely clipped to save bandwidth]
> On Fri, 11 Aug 2006 14:07:16 GMT, "Eric G."
> <NgOrSePeAnM99@Zoptonline.Znet> wrote:
>
>>"Tom" <tjwitman@bellsouth.net> wrote in
>>news:5oRCg.4515$ID1.1966@bignews2.bellsouth.ne t:
>>
>>> To do it right, you need to start from scratch, which means you need
>>> a good set of gauges and know how to use them. You also need a
>>> vacuum pump to hook up to the system, which will cost you about $400
>>> or so. You really do need to know the procedure so get a shop manual
>>> for the car. If you do it wrong, and open up the high pressure side
>>> to the can of freon, you're dead! It's really not that hard but you
>>> just need to know the steps and precautions.
>>
>>Sorry, but you don't need a vacuum pump. If you have good gauges,
>>hooked up to the right ports, know the ambient air temp., and how much
>>charge the system is supposed to have, you can fill the system
>>properly without a problem.
>>
>>Eric
>
> You need a good sensitive refrigerant scale. Virtually all automotive
> AC systems are charged by weight, not pressure/temperature.
>
> gerry

From the factory, yes. In the field, it can actually be better to use
pressure/temperature. What do you propose? Evacuate the entire system and
add X ounces of refrigerant?

Eric G. wrote:
> gerry <gerrrry__net@gogood.com> wrote in
> news:ds8pd25orts9h32ivp6t4janjjmhua6cch@4ax.com:
>
>
>>[original post is likely clipped to save bandwidth]
>>On Fri, 11 Aug 2006 14:07:16 GMT, "Eric G."
>><NgOrSePeAnM99@Zoptonline.Znet> wrote:
>>
>>
>>>"Tom" <tjwitman@bellsouth.net> wrote in
>>>news:5oRCg.4515$ID1.1966@bignews2.bellsouth.net :
>>>
>>>
>>>>To do it right, you need to start from scratch, which means you need
>>>>a good set of gauges and know how to use them. You also need a
>>>>vacuum pump to hook up to the system, which will cost you about $400
>>>>or so. You really do need to know the procedure so get a shop manual
>>>>for the car. If you do it wrong, and open up the high pressure side
>>>>to the can of freon, you're dead! It's really not that hard but you
>>>>just need to know the steps and precautions.
>>>
>>>Sorry, but you don't need a vacuum pump. If you have good gauges,
>>>hooked up to the right ports, know the ambient air temp., and how much
>>>charge the system is supposed to have, you can fill the system
>>>properly without a problem.
>>>
>>>Eric
>>
>>You need a good sensitive refrigerant scale. Virtually all automotive
>>AC systems are charged by weight, not pressure/temperature.
>>
>>gerry
>
>
> From the factory, yes. In the field, it can actually be better to use
> pressure/temperature. What do you propose? Evacuate the entire system and
> add X ounces of refrigerant?

I believe that is the correct way to do it. That obviously isn't what
happens with the DIY kits.

Matt

Matt Whiting <whiting@epix.net> wrote in
news:9a6Dg.457$Db4.41075@news1.epix.net:

>> From the factory, yes. In the field, it can actually be better to
>> use pressure/temperature. What do you propose? Evacuate the entire
>> system and add X ounces of refrigerant?
>
> I believe that is the correct way to do it. That obviously isn't what
> happens with the DIY kits.
>
> Matt

Absolutely, it is the right way to do it. We were talking about DIY from
the start, or so I thought. Although gauges can cost hundreds of dollars,
you can usually find someone that will let you borrow a set, and then you
can just use a can of R-134a from an auto supply.

Eric

Eric G. wrote:
> "Tom" <tjwitman@bellsouth.net> wrote in
> news:5oRCg.4515$ID1.1966@bignews2.bellsouth.net:
>
>> To do it right, you need to start from scratch, which means you need a
>> good set of gauges and know how to use them. You also need a vacuum
>> pump to hook up to the system, which will cost you about $400 or so.
>> You really do need to know the procedure so get a shop manual for the
>> car. If you do it wrong, and open up the high pressure side to the
>> can of freon, you're dead! It's really not that hard but you just
>> need to know the steps and precautions.
>
> Sorry, but you don't need a vacuum pump. If you have good gauges, hooked
> up to the right ports, know the ambient air temp., and how much charge the
> system is supposed to have, you can fill the system properly without a
> problem.

You might not need a vacuum pump for your AC service, but I sure do.

Of course, I like my AC cold and my pumps happy and long lasting. Iced
up orifice tubes suck.

JS

[original post is likely clipped to save bandwidth]
On Fri, 11 Aug 2006 16:58:09 GMT, "Eric G."
<NgOrSePeAnM99@Zoptonline.Znet> wrote:

>gerry <gerrrry__net@gogood.com> wrote in
>news:ds8pd25orts9h32ivp6t4janjjmhua6cch@4ax.com :
>
>> [original post is likely clipped to save bandwidth]
>> On Fri, 11 Aug 2006 14:07:16 GMT, "Eric G."
>> <NgOrSePeAnM99@Zoptonline.Znet> wrote:
>>
>>>"Tom" <tjwitman@bellsouth.net> wrote in
>>>news:5oRCg.4515$ID1.1966@bignews2.bellsouth.net :
>>>
>>>> To do it right, you need to start from scratch, which means you need
>>>> a good set of gauges and know how to use them. You also need a
>>>> vacuum pump to hook up to the system, which will cost you about $400
>>>> or so. You really do need to know the procedure so get a shop manual
>>>> for the car. If you do it wrong, and open up the high pressure side
>>>> to the can of freon, you're dead! It's really not that hard but you
>>>> just need to know the steps and precautions.
>>>
>>>Sorry, but you don't need a vacuum pump. If you have good gauges,
>>>hooked up to the right ports, know the ambient air temp., and how much
>>>charge the system is supposed to have, you can fill the system
>>>properly without a problem.
>>>
>>>Eric
>>
>> You need a good sensitive refrigerant scale. Virtually all automotive
>> AC systems are charged by weight, not pressure/temperature.
>>
>> gerry
>
>From the factory, yes. In the field, it can actually be better to use
>pressure/temperature. What do you propose? Evacuate the entire system and
>add X ounces of refrigerant?

Weigh in is the ONLY proper way!!! That is also why legal recharging
places have recovery/recycle equipment. In the US, the EPA actually
requires 609 certification to work on MVAC equipment such as an
automobile. "Recharge kits" exist because R-141a does not need a
certification to purchase and the EPA overlooks the private usage.

Weigh-in is the only way to get a full charge without overcharging!

Automotive systems use an accumulator or receiver and TXV metering.
Since this setup keeps a reserve of liquid, the amount of reserve can
not be determined via pressure. Too little and you will get less than
desired capacity. Too much and you get liquid in the compressor and
destroy it. Pressure remains the same without regard to liquid level in
the receiver or accumulator.

gerry

--

Personal home page - http://gogood.com

gerry misspelled in my email address to confuse robots

[original post is likely clipped to save bandwidth]
On Fri, 11 Aug 2006 19:44:06 -0500, JS <jsuter@intrastardot.net> wrote:

>Eric G. wrote:
>> "Tom" <tjwitman@bellsouth.net> wrote in
>> news:5oRCg.4515$ID1.1966@bignews2.bellsouth.net:
>>
>>> To do it right, you need to start from scratch, which means you need a
>>> good set of gauges and know how to use them. You also need a vacuum
>>> pump to hook up to the system, which will cost you about $400 or so.
>>> You really do need to know the procedure so get a shop manual for the
>>> car. If you do it wrong, and open up the high pressure side to the
>>> can of freon, you're dead! It's really not that hard but you just
>>> need to know the steps and precautions.
>>
>> Sorry, but you don't need a vacuum pump. If you have good gauges, hooked
>> up to the right ports, know the ambient air temp., and how much charge the
>> system is supposed to have, you can fill the system properly without a
>> problem.
>
>You might not need a vacuum pump for your AC service, but I sure do.
>
>Of course, I like my AC cold and my pumps happy and long lasting. Iced
>up orifice tubes suck.
>
>JS


Automotive AC's don't use orifice tubes, they use TXV's for metering.

gerry

--

Personal home page - http://gogood.com

gerry misspelled in my email address to confuse robots