From: aarcuda69062 on
In article <h90es1$fqd$1(a)news.eternal-september.org>,
"Ray O" <rokigawa(a)NOSPAMtristarassociates.com> wrote:

> "Steve Smith Richmond VA" <Cabinut(a)verizon.net> wrote in message
> news:2f60bcfa-55e4-4e8a-9ca6-cc40a568d848(a)p9g2000vbl.googlegroups.com...
> >
> >> To find out which one, we need to know the year of the truck.
> >
> > It's a 1997.
>
> I'm pretty sure that the 1997 T100's AC system uses R34-A.
>
> Some things you should be aware of:
>
> - You are supposed to have an EPA certification to work on AC systems.

Depends on the state. As far as the EPA is concerned, certification
only applies if the work is done for pay (consideration), a
do-it-yourselfer is not obligated by law or required to be certified.
States such as Wisconsin (hi neighbor) have stricter laws regarding
mobil air conditioning systems, we also have fewer problems with DIYers
screwing things up and adding contaminants such as seal sweller and
sealant.

> - There are substantial fines for venting refrigerant to the atmosphere.

Applies to service personnel/shops, doesn't apply to back yard bubbas,
again, YMMV depending on state.

> - The proper way to service the AC system is with a refrigerant recovery
> machine, vacuum pump, and AC gauges for the type of refrigerant you are
> using.
> - If the system has been exposed to the atmosphere for any length of time,
> the desiccant in the receiver drier may be saturated and so moisture in the
> system may cause corrosion or freezing at the expansion valve.
> - over-charging the AC system can cause physical damage to the person doing
> the charging and to the AC system.
> - wear safety goggles when working on a pressurized AC system!

No disagreement any any of that!
From: Jeff Strickland on

"Ray O" <rokigawa(a)NOSPAMtristarassociates.com> wrote in message
news:h90lf1$9n3$1(a)news.eternal-september.org...
>
> "Jeff Strickland" <crwlrjeff(a)yahoo.com> wrote in message
> news:h90jpl$rb3$1(a)news.eternal-september.org...
>>
>> "Ray O" <rokigawa(a)NOSPAMtristarassociates.com> wrote in message
>> news:h90es1$fqd$1(a)news.eternal-september.org...
>>>
>>> "Steve Smith Richmond VA" <Cabinut(a)verizon.net> wrote in message
>>> news:2f60bcfa-55e4-4e8a-9ca6-cc40a568d848(a)p9g2000vbl.googlegroups.com...
>>>>
>>>>> To find out which one, we need to know the year of the truck.
>>>>
>>>> It's a 1997.
>>>
>>> I'm pretty sure that the 1997 T100's AC system uses R34-A.
>>>
>>> Some things you should be aware of:
>>>
>>> - You are supposed to have an EPA certification to work on AC systems.
>>> - There are substantial fines for venting refrigerant to the atmosphere.
>>> - The proper way to service the AC system is with a refrigerant recovery
>>> machine, vacuum pump, and AC gauges for the type of refrigerant you are
>>> using.
>>> - If the system has been exposed to the atmosphere for any length of
>>> time, the desiccant in the receiver drier may be saturated and so
>>> moisture in the system may cause corrosion or freezing at the expansion
>>> valve.
>>> - over-charging the AC system can cause physical damage to the person
>>> doing the charging and to the AC system.
>>> - wear safety goggles when working on a pressurized AC system!
>>> --
>>
>>
>>
>> Ray,
>>
>> You can drop by your local autoparts store and buy small (14.5 oz.) cans
>> of R134a and a hose to connect it to the Low Pressure Port on the system.
>> If the system is sound but merely needs a refresher can of juice (R134a)
>> because it can seep out over time, then the small can is enough to get
>> the system going again. There is no reason to vent anything, no need to
>> evacuate, no need for anything but a fresh can of juice.
>
> I am aware of the small cans of refrigerant for do-it-yourselfers. We
> used to refer to them as "suicide cans" because under the old system, it
> was possible to hook it up to the high pressure side with potentially
> explosive results.
>
> If you re-read my post, note that I said that the **proper** way to
> service the AC system...
>
> I could have added that the amateur way that may or may not work to
> service the AC systrem is to use those D-I-Y cans, but I generally do not
> give advice that I think is a bad idea, and the automakers and the EPA
> agree.
>
> There are several reasons I think using suicide cans is a bad idea.
>
> First, IMO, someone who has to ask what type of refrigerant to use without
> the ability or willingness to find the answer probably shouldn't be
> messing with a system that could be costly to fix if improper procedures
> are followed.
>

I'm with you on that one. My first post was, "If you gotta ask ..."



> Second, there is no way to tell the mass of the refrigerant remaining in
> the system so there is no way to tell how much should be added. The
> factory repair manual will tell you to evacuate and recover the
> refrigerant and will not suggest topping off refrigerant. Are you aware
> that too much refrigerant can also cause problems with AC system function?
>

The Low Pressure Gauge will tell you when you are done adding refridgerant.



> Third, the other reason that the system is evacuated and a vacuum drawn is
> to check and quantify the integrity of the system without needlessly
> releasing refrigerant to the atmosphere.
>
> Fourth, if you add suicide cans and the system is leaking, not only have
> you wasted the money spent on the suicide cans, you have carelessly
> released harmful gases to the atmosphere, which the EPA frowns upon.
>
> Fifth, if there is atmosphere in the system, adding suicide cans does not
> purge the atmosphere so you are in effect trapping moisture and
> non-refrigerant gases in the system.
>

If the system had a normal leak-down over 13 years (the OP said he has a '97
and the current productin is 2010, then it is 13 years, else it is 12) then
logic dictates that there should be nothing in the system except
refridgerant and oil.

Whatever. The main point here is that the OP had to ask, and this should
give him pause about servicing the system himself. I would not hesitate to
invest a couple of bucks in a can of juice and the hose to put it in with.
(I recently bought 4 cans for $5.00 each, on sale. The cost to service the
system at home is very low, the danger is virtually non-existant, and the
odds of being successful are very high.






From: Ray O on

"Jeff Strickland" <crwlrjeff(a)yahoo.com> wrote in message
news:h90p7l$9ae$1(a)news.eternal-september.org...
>
> "Ray O" <rokigawa(a)NOSPAMtristarassociates.com> wrote in message
> news:h90lf1$9n3$1(a)news.eternal-september.org...
>>
>> "Jeff Strickland" <crwlrjeff(a)yahoo.com> wrote in message
>> news:h90jpl$rb3$1(a)news.eternal-september.org...
>>>
>>> "Ray O" <rokigawa(a)NOSPAMtristarassociates.com> wrote in message
>>> news:h90es1$fqd$1(a)news.eternal-september.org...
>>>>
>>>> "Steve Smith Richmond VA" <Cabinut(a)verizon.net> wrote in message
>>>> news:2f60bcfa-55e4-4e8a-9ca6-cc40a568d848(a)p9g2000vbl.googlegroups.com...
>>>>>
>>>>>> To find out which one, we need to know the year of the truck.
>>>>>
>>>>> It's a 1997.
>>>>
>>>> I'm pretty sure that the 1997 T100's AC system uses R34-A.
>>>>
>>>> Some things you should be aware of:
>>>>
>>>> - You are supposed to have an EPA certification to work on AC systems.
>>>> - There are substantial fines for venting refrigerant to the
>>>> atmosphere.
>>>> - The proper way to service the AC system is with a refrigerant
>>>> recovery machine, vacuum pump, and AC gauges for the type of
>>>> refrigerant you are using.
>>>> - If the system has been exposed to the atmosphere for any length of
>>>> time, the desiccant in the receiver drier may be saturated and so
>>>> moisture in the system may cause corrosion or freezing at the expansion
>>>> valve.
>>>> - over-charging the AC system can cause physical damage to the person
>>>> doing the charging and to the AC system.
>>>> - wear safety goggles when working on a pressurized AC system!
>>>> --
>>>
>>>
>>>
>>> Ray,
>>>
>>> You can drop by your local autoparts store and buy small (14.5 oz.) cans
>>> of R134a and a hose to connect it to the Low Pressure Port on the
>>> system. If the system is sound but merely needs a refresher can of juice
>>> (R134a) because it can seep out over time, then the small can is enough
>>> to get the system going again. There is no reason to vent anything, no
>>> need to evacuate, no need for anything but a fresh can of juice.
>>
>> I am aware of the small cans of refrigerant for do-it-yourselfers. We
>> used to refer to them as "suicide cans" because under the old system, it
>> was possible to hook it up to the high pressure side with potentially
>> explosive results.
>>
>> If you re-read my post, note that I said that the **proper** way to
>> service the AC system...
>>
>> I could have added that the amateur way that may or may not work to
>> service the AC systrem is to use those D-I-Y cans, but I generally do not
>> give advice that I think is a bad idea, and the automakers and the EPA
>> agree.
>>
>> There are several reasons I think using suicide cans is a bad idea.
>>
>> First, IMO, someone who has to ask what type of refrigerant to use
>> without the ability or willingness to find the answer probably shouldn't
>> be messing with a system that could be costly to fix if improper
>> procedures are followed.
>>
>
> I'm with you on that one. My first post was, "If you gotta ask ..."
>
>
>
>> Second, there is no way to tell the mass of the refrigerant remaining in
>> the system so there is no way to tell how much should be added. The
>> factory repair manual will tell you to evacuate and recover the
>> refrigerant and will not suggest topping off refrigerant. Are you aware
>> that too much refrigerant can also cause problems with AC system
>> function?
>>
>
> The Low Pressure Gauge will tell you when you are done adding
> refridgerant.
>

A pressure gauge, as the name implies, indicates the pressure in the system.
As you probably know, pressure varies with temperature, the condition of the
compressor, valves, and other components and contaminants in the system.
For example, if moisture has seeped into the system, the moisture can freeze
in the expansion valve, increasing pressure in the low side. A leaking
expansion valve could reduce low side pressure, and someone who is using
just low side pressure as an indicator of how much refrigerant to add would
add too much refrigerant.
>
>> Third, the other reason that the system is evacuated and a vacuum drawn
>> is to check and quantify the integrity of the system without needlessly
>> releasing refrigerant to the atmosphere.
>>
>> Fourth, if you add suicide cans and the system is leaking, not only have
>> you wasted the money spent on the suicide cans, you have carelessly
>> released harmful gases to the atmosphere, which the EPA frowns upon.
>>
>> Fifth, if there is atmosphere in the system, adding suicide cans does not
>> purge the atmosphere so you are in effect trapping moisture and
>> non-refrigerant gases in the system.
>>
>
> If the system had a normal leak-down over 13 years (the OP said he has a
> '97 and the current productin is 2010, then it is 13 years, else it is 12)
> then logic dictates that there should be nothing in the system except
> refridgerant and oil.
>

At this point, we do not have enough information about the vehicle to know
whether or not the system had a normal leak down, if the OP is the original
owner and knows its complete service history (including whether or not the
AC system has been serviced in the past), the amount of refrigerant
remaining in the system, and how long the system has been low and how low on
refrigerant.

If the pressure in the system is at or below atmospheric pressure and has
been in this state long enough, moisture can accumulate in the system.

> Whatever. The main point here is that the OP had to ask, and this should
> give him pause about servicing the system himself. I would not hesitate to
> invest a couple of bucks in a can of juice and the hose to put it in with.
> (I recently bought 4 cans for $5.00 each, on sale. The cost to service the
> system at home is very low, the danger is virtually non-existant, and the
> odds of being successful are very high.
>
I've seen a pretty fair number of systems that were messed up by people who
used suicide cans without the proper equipment. There are very few things I
wouldn't attempt to service on my vehicles at home, and charging the AC
system is one of them because I do not have the proper equipment.
--

Ray O
(correct punctuation to reply)