Re: [Chrysler300] 300 G A/C
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Re: [Chrysler300] 300 G A/C

Jeep uses an orifice tube and accumulator system, cheap to produce and pretty much problem free.  Odor indicates you need to clean out the Evap. coil area, there are many good products to help with this.  ignoring this can lead to evaporator failure.

   Our old Chrysler Airtemp expansion valve and EPR systems were over engineered and had great heater box drainage.  Pretty much a bullet proof system.

  Before the refrigerant recovery machines, we used Robinair Dial-a-charge, refrigerant system. After evacuating the system. You would fill the clear reverse graduated cylinder with the correct amount of refrigerant, turn on the pressure controlled heater and you could quickly charge your a/c system. This worked very well. The sight glass could be observed, but was not the necessarily stopping point, usually several more ounces of refrigerant were needed to complete the full charge.

From: John Grady <jkg@xxxxxxxxxxxxxxxxx>
Sent: Monday, August 28, 2017 5:51 PM
Cc: Chrysler300@xxxxxxxxxxxxxxx
Subject: RE: [Chrysler300] 300 G A/C

Re: Freon levels in AC.

While the following might seem strange to pros and newbies both, I struggled with this ?how much Freon is in it ? question, for many years, pressure gauges do not tell you, ----This due to JUNK mopar evaporators on multiple JEEPS. They are made of thin aluminum, almost aluminum foil in my opinion, which then sit in their own toilet drain water as the drain design for AC condensation  is also junk.(aka  ?that smell? ) So corrosion from outside and inside  develops a pin hole Freon leak in evap core . At first, no AC one day---so you recharge , ok for 3-6 months. Repeat, but now 5 months then 3 months etc etc. Pin holes growing. Due to still more genius engineering in JEEPS, it is 2000$ at  stealership to pull entire dash and steering wheel out  , to get at the flimsy 39$ AC evap or heater core..Heater core another ?sure to fail? loser from modern mopar. So at ~ ten + years old you have both problems , 2000 each, a year apart, (so smarten up do both at once ) and then at 140k  piston skirts break off at oil ring line , (had been redesigned ?to lighten them?), another 2k+$, or  1998 to 2002 head cracks , leaks antifreeze into oil. Whole new engine required for that one. They  ?Redesigned the head?. Why? They took the best 4.0 engine ever made , AMC six, up there with the slant, good engine since the 50?s/ 60?s , until 97 at least, they finally wrecked it at end. 4.0 was making all the new ?100k and worn out ? V6  ones  look awful.(they are) .  Old one, a  97 4.0 inline six , made it to 300k in one Grand Cherokee jeep I had  .

Anyway, how to tell Freon levels gets to be a monthly challenge , with your great JEEP mini leak in summer,  avoiding the 2k$ bill?..for a while . So , after struggling lot, had a new idea; new to me anyway.

Refrigerant coming out of condenser in front ought to be pretty hot , going into the receiver /dryer  , where it is stored, say when starting AC , and the car up from cold, so tried feeling receiver can with my hand at startup. (later it is going to be all evenly hot) Idea was right ---it gets hot. But it very soon gets hot all over--- refrigerant must spray hot liquid inside it ,and heat spreads out  in a metal, a good conductor of heat. But half way there!  So decided to try carefully spraying ice cold water on receiver can while AC is operating. Viola!! Where liquid sits in puddle at bottom, it will stay pretty hot, but at top half of can it gets cold from water being a good coolant  , and only a thin layer is on the inside, not a pond of hot Freon , like at bottom. After a while I got good at this. Add a can, you can feel it rise up, and stop when 1? from top (arbitrary, my guess) .If indication of level and this concept , are not TOTALLY  clear to you, do NOT do this.

It was manna from heaven for me?.I can now tell reserve Freon level inside the receiver?no gauges.  If low,  throw a can in. One of those temp guns and water might work like this too.

Agree sight glass is terrific, if you have one. But once bubbles go away, how much more could you add?

Hope this experiment helps somebody?

Kinda cool!

From: RICK AND DEBBIE CLAPHAM [mailto:rixpac@xxxxxxx]
Sent: Thursday, August 24, 2017 9:07 PM
To: Ray Jones; John Grady
Cc: Chrysler300@xxxxxxxxxxxxxxx
Subject: Re: [Chrysler300] 300 G A/C

I am MACS and IMACA certified, mobile refrigeration mechanic, fourty plus years and hundreds and possibly thousands of repairs. You all have good points. Do not forget the sight glass in the high side filter/drier/receiver, as well as the EPR valve can fool you, pressure wise. The sight glass tells you what you need to know. Our Airtemp condensers will hold another pound if needed. The aftermarket units? Good luck!


From: Chrysler300@xxxxxxxxxxxxxxx <Chrysler300@xxxxxxxxxxxxxxx> on behalf of John Grady jkg@xxxxxxxxxxxxxxxxx [Chrysler300] <Chrysler300-noreply@xxxxxxxxxxxxxxx>
Sent: Thursday, August 24, 2017 4:34 PM
To: Ray Jones
Cc: chrysler300@xxxxxxxxxxxxxxx
Subject: Re: [Chrysler300] 300 G A/C

Just quickly, pressure readings do not tell you charge level, but I agree throwing in one can like that --if you know for sure low can fix it. If it is not low you can overcharge , = disaster . The only way to correctly charge is by weight of refrigerant and a scale -which they do in an empty system or first pull out what is in there with suction  AC machine     ( a law now) . Excess liquid refrigerant is kept in the car receiver / dryer tank , by design .

It is like a propane tank . Pressure is the same almost empty or full . Pressure is Set only by temp of propane ,or refrigerant  not by how much is in tank .. for things that are liquid at room temp under pressure , but change to gas  if pressure drops . Why gas comes out in your grill , not liquid . And flame stays about the same size ( same pressure) as the liquid tank empties on a  hand held propane torch . And gets cold. Straight compressed gas ( oxygen) non liquified yes pressure tells you % full in cu ft .

Somewhere in FSM is weight in oz of new charge .. about 2 cans + usually. By way of understanding , not critique .

Sent from my iPhone

On Aug 24, 2017, at 5:08 PM, Ray Jones 1970hurst@xxxxxxxxx<mailto:1970hurst@xxxxxxxxx> [Chrysler300] <Chrysler300-noreply@xxxxxxxxxxxxxxx<mailto:Chrysler300-noreply@xxxxxxxxxxxxxxx>> wrote:

Go to Walmart*, there you will find a 134-A refill kit.

It consists of a can of 134*A, a gauge, hose and handle.

Hook it up to your system, Will only attach to one connector.

Follow directions (Nobody will see you doing it)
What you want to do is watch the gauge and see what the pressure is while it's running.

If it's low, pull the trigger and add Freon until it gets the pressure up to the range it wants.

The gauge has the ranges marked on it, so it's easy.

When finished, but the rig in you tool box for future use, you can add more bottles when you need them, I get them on sale @ $3.85 or less @ Atwoods.

If you have a 2 gauge pro system, look for the pressure to be 1/2 ambient air temp on the low side and double or more on the high side. Some charts I just looked at are showing pressure to be triple ambient air temp.
And of course you add Freon thru the gauges.

On Thu, Aug 24, 2017 at 3:44 PM, 'Rich Barber' c300@xxxxxxx<mailto:c300@xxxxxxx> [Chrysler300] <Chrysler300-noreply@xxxxxxxxxxxxxxx<mailto:Chrysler300-noreply@xxxxxxxxxxxxxxx>> wrote:

My understanding is that R-134 refrigerant has different thermodynamic properties and expands to a somewhat higher temperature than does R-12 from a given pressure.  Newer cars adjust for that with larger evaporator coils and flow rates to achieve cooling but the outlet air temperature will never be 40F again.  The capillary expansion tube is no-doubt different, also.  Our ?99 Wrangler FA/C starts cooling immediately.  Our ?05 Durango starts cooling slowly but eventually gets the job done.  Both use R-134.

No doubt, R-12 was a great refrigerant for cars.  Eventually, nearly all refrigerants will be vented to atmosphere.  Some may be broken down but the chlorine will still go to the atmosphere and break down the ozone (O3) layer (or so they say).  Changeover was on or about 1-1-94.

Rich Barber, BSME

Brentwood CA

From: Chrysler300@xxxxxxxxxxxxxxx<mailto:Chrysler300@xxxxxxxxxxxxxxx> [mailto:Chrysler300@xxxxxxxxxxxxxxx<mailto:Chrysler300@xxxxxxxxxxxxxxx>] On Behalf Of Val Jeffers edward1108@xxxxxxxxx<mailto:edward1108@xxxxxxxxx> [Chrysler300]
Sent: Thursday, August 24, 2017 10:38 AM
To: Chrysler 300 List <chrysler300@xxxxxxxxxxxxxxx<mailto:chrysler300@xxxxxxxxxxxxxxx>>
Subject: [Chrysler300] 300 G A/C


               The service manual states 45 ounces of R12 Freon is the capacity. My question is, since converting to R134 several years ago, is that still the correct number ? I think mine is running low and want to recharge as it is blowing cool but not cold as it should be.


                                                                                Val Jeffers

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Ray Jones. Y'all come on down an see us. Ya hear?

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