1996 Silverado air conditioner at idle

I have a 1996 Silverado. Replaced compressor, receiver/dryer, and
condensor with autozone replacements. Flushed system. Replaced one of
the lines. Seems to cool ok at interstate speed but at idle it does
not. It has been in the 90's here but I feel it should cool better
than this. I bought a HF scale and charged by weight. However, becasue
it is hard to estimate how much is coming out of a can I think I have
2 extra ounces in it. Would that cause this problem? It cooled fine I
think when I fixed the air but temps were not in the 90's. Could the
fan clutch cause this and how do I tell if it is bad?

I have not put guages on it yet. What shoudl the pressures be?

I appreciate any help!

On 06/10/2011 12:00 PM, stryped wrote:
> I have a 1996 Silverado. Replaced compressor, receiver/dryer, and
> condensor with autozone replacements. Flushed system. Replaced one of
> the lines. Seems to cool ok at interstate speed but at idle it does
> not. It has been in the 90's here but I feel it should cool better
> than this. I bought a HF scale and charged by weight. However, becasue
> it is hard to estimate how much is coming out of a can I think I have
> 2 extra ounces in it. Would that cause this problem? It cooled fine I
> think when I fixed the air but temps were not in the 90's. Could the
> fan clutch cause this and how do I tell if it is bad?
>
> I have not put guages on it yet. What shoudl the pressures be?
>
> I appreciate any help!

gotta ask - did you evacuate before charging?


--
nomina rutrum rutrum

On Jun 10, 3:14*pm, m6onz5a > wrote:
> On Jun 10, 3:00*pm, stryped > wrote:
>
> > I have a 1996 Silverado. Replaced compressor, receiver/dryer, and
> > condensor with autozone replacements. Flushed system. Replaced one of
> > the lines. Seems to cool ok at interstate speed but at idle it does
> > not. It has been in the 90's here but I feel it should cool better
> > than this. I bought a HF scale and charged by weight. However, becasue
> > it is hard to estimate how much is coming out of a can I think I have
> > 2 extra ounces in it. Would that cause this problem? It cooled fine I
> > think when I fixed the air but temps were not in the 90's. Could the
> > fan clutch cause this and how do I tell if it is bad?
>
> > I have not put guages on it yet. What shoudl the pressures be?
>
> > I appreciate any help!
>
> Four Seasons part # 38903 for the auto adjusting orifice tube.
>
> Chas

I never bought a new orface tube becasue the new condensor had one
already in there but I wish I had now. Still, something does not seem
right. It is blowing hot air out of the vents for the first 4-5 miles
or so.

On Fri, 10 Jun 2011 13:23:27 -0700 (PDT), stryped >
wrote:

>On Jun 10, 3:13Â*pm, Vic Smith > wrote:
>> On Fri, 10 Jun 2011 12:00:20 -0700 (PDT), stryped >
>> wrote:
>>
>> >I have a 1996 Silverado. Replaced compressor, receiver/dryer, and
>> >condensor with autozone replacements. Flushed system. Replaced one of
>> >the lines. Seems to cool ok at interstate speed but at idle it does
>> >not. It has been in the 90's here but I feel it should cool better
>> >than this. I bought a HF scale and charged by weight. However, becasue
>> >it is hard to estimate how much is coming out of a can I think I have
>> >2 extra ounces in it. Would that cause this problem? It cooled fine I
>> >think when I fixed the air but temps were not in the 90's. Could the
>> >fan clutch cause this and how do I tell if it is bad?
>>
>> >I have not put guages on it yet. What shoudl the pressures be?
>>
>> >I appreciate any help!
>>
>> I never got satisfaction from pressure specs. Â*Always 5-10 pounds off.
>> I Â*put in just under the called-for system refrigerant weight, and use
>> a thermometer in the vent after the temp has stabilized.
>> Then add a little at a time until the temp doesn't drop. Â*Done.
>> That's all at idle. Â*You'll always have cooler air at speed.
>> Refrigerant is working harder and air pulls away heat from the
>> vehicle.
>> A/C should kick idle up a bit.
>> When your car has been sitting in the sun awhile it takes some time
>> for the components to cool.
>> Thermometer is the only way to know. Â*Takes away doubt.
>> You're not even sure it's cooling right on the interstate from what
>> you said. Â*Too much "seems" and "feels."
>>
>> --Vic
>
>When I first repaired this thing vent tem was around 42-45.
>
>Now going down the road it is 50-60 but will double check.
>
>SHould I put more freon in it?

Measure the temp. Your 42-45 means nothing if it was measured when
the outside air was less than now.
You just might be imagining things.
Are you sweating in there?
I don't know your truck, but when I've had a fan clutch its main
purpose was for engine cooling, so if you've got an engine temp gauge
that should tell the story on the clutch.
My newer cars kick on the electric fans when the A/C is turned on.
Did you put dyed refrigerant in?
If you find the temp is really rising wait until it's worthless, then
refill with dyed refrigerant and find the leak.
Look at the compressor shaft first, then connections, then condenser.
I had to take 2 rebuilt compressors back when the shafts started
leaking after some weeks. One got me on my Florida vacation.
I raised hell and kicked in maybe 50 bucks more for a new one.
I'll never buy another rebuilt compressor.
Then they put non A/C o-rings in the box with a new dryer, so that job
cooled for only a couple weeks.
Fixed that, and after a couple months temp went up again.
Found a small leak in the condenser and replaced that.
Been good since then.
Went though a lot of refrigerant, and that stuff is expensive.
So if you're leaking, check it all.
I use this,
http://www.autotoolworld.com/Interdy...s_p_94869.html
Hard to find. First bought it Track Auto, but I never see it carried
anymore. Bought a couple cans on E-Bay a few years ago and have
plenty left. You don't need a dye injector, and don't pay a goofy
price for pre-dyed 134.
Put in a 12 ouncer of 134, shoot this in for a couple seconds, then
load the rest of your 134.
A good black light is better than the little penlights.
My kid had a 4 footer from his teen-age days and we use that.
But don't do anything until you're sure it's failing.

--Vic

stryped wrote:
> On Jun 10, 3:14 pm, m6onz5a > wrote:
>> On Jun 10, 3:00 pm, stryped > wrote:
>>
>>> I have a 1996 Silverado. Replaced compressor, receiver/dryer, and
>>> condensor with autozone replacements. Flushed system. Replaced one of
>>> the lines. Seems to cool ok at interstate speed but at idle it does
>>> not. It has been in the 90's here but I feel it should cool better
>>> than this. I bought a HF scale and charged by weight. However, becasue
>>> it is hard to estimate how much is coming out of a can I think I have
>>> 2 extra ounces in it. Would that cause this problem? It cooled fine I
>>> think when I fixed the air but temps were not in the 90's. Could the
>>> fan clutch cause this and how do I tell if it is bad?
>>> I have not put guages on it yet. What shoudl the pressures be?
>>> I appreciate any help!
>> Four Seasons part # 38903 for the auto adjusting orifice tube.
>>
>> Chas
>
> I never bought a new orface tube becasue the new condensor had one
> already in there but I wish I had now. Still, something does not seem
> right. It is blowing hot air out of the vents for the first 4-5 miles
> or so.

That is 100% normal. Your truck is setting out in the heat and all of
the interior, ductwork, and the rest are all HOT. It takes a bit of
cooling for all of that to get that thermal mass cool enough that it
isn't heating the passing air.

Charging by weight is a baseline. Then you connect up the gauges and a
temp probe and see what you really have.

What did you flush the system with?
When you applied the vacuum did you make SURE there were no leaks?
I assume you didn't flush the system with the drier in line correct? If
you did have the drier in line then you will need a new one.

First step. Get a temp chart.
http://www.glacierbay.com/ptchart134a.asp
http://www.csgnetwork.com/r134apresstempconv.html

Follow the testing procedure and see what you actually have for vent temps.
See what the chart says you should have for your ambient temp. in both
temp and pressures.

Then check over the system if things don't look right. Also check over
the various doors in the system. Making sure the A/C works is a real PIA
if a blend door is open when it's supposed to be closed....


--
Steve W.