How to Recharge your Air Conditioning

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ravingmadman

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We've had two threads on problematic A/C in the last couple days, and it is my belief that most A/C just needs a recharge, or it is an obvious problem, otherwise you need a shop to help you diagnose the problem. Not a whole lot of middle ground. If you want to understand how AC works, PM me, but this isn't the time/place. Here's how you do it, in really, really basic steps...

Go to Schucks and buy a really, really big can of 134a Refridgerant. You will need two big cans (at least) if your system is totally discharged. Get the one with the pistol grip, trigger, and pressure guage (like in the picture). It is reusable, so in the future if you're A/C isn't quite getting there, you can just buy a short bottle (like I did) and plus up your system.

Buy this:


Start your hoe, and turn the AC to max, if you have rear AC turn it to max too. Find the "low side service port" on the top of the engine (don't ask me, I'm not bankrupt:happy175:) here (click on the link- the arrow isn't really showing up in the thumbnail):


Unscrew the cap on it:


I recommend you put on some insulated gloves, because your hands will get cold coming up. Connect your bottle and hose thingy to it. It works like a regular high-pressure fitting like on an air compressor hose- pull the ring back, push the hose on the port until it clicks, then release the ring to lock the hose on the port. You will be able to read the AC system's pressure (or lack of) at this point. For about $20. :headbang:


As the pump cycles, you'll be able to watch the system charge and discharge on the pressure guage. The warning labels on the bottle are going to put the fear of the Holy Spirit into you warning you not to overcharge the system. I recommend you flagrantly disregard these warnings. Rock the bottle from upside down (12 o'clock) to it's side (3 o'clock) back and forth about every second, nice and gently. You'll feel the oil inside sloshing around. Pull the trigger on the bottle, and the pressure will drop to zero. Keep rocking the bottle back and forth so even amounts of gas and liquid enter the system.

Do this until your pressure is cycling in the blue range of the pressure gauge (25-45PSI) and/or your pump is staying on full time. I am not sure what the book says, but this is the point at which I stop, and get back in my hoe to enjoy the cool air.

Troubleshooting no pressure/no pump operation:
If your compressor isn't turning on, there's a safety that disables the pump if the pressure gets too low, so don't fret. When you connect the bottle up, and pull the trigger, when there's no pump operation, you'll develop really high pressure (150PSI+) until the system evens itself out. I had zero pressure, then put a 2-second burst in, not knowing any better, and my pressure spiked to about 150. I just kept adding though (i figured at least if something broke, I'd know what to fix, right?), and eventually the compressor started (that's a really good feeling) and the pressure immediately dropped. Then as the system filled, the needle fluctuated less and less with the pump cycles, until it was finally bouncing in the blue, and then staying pegged halfway between, with the compressor running 100% of the time. And some very cold air coming out.

Hope that helps!!! Best of luck!!:drunk:

Kjell
 

foreverfalcon40

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Ok...your A/C will be cool!

If you want ice cold you will need to bring it to a shop and have them hook it up to the machine.

Vaccum from the machine sucks the 134 into the system.
 

MarkR

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Ok I decided to do this yesterday. My system was blowing at about 58-60 degrees. I filled mine per the chart on the can. It was over 100 in the garage so I filled to 55psi. Now the blower in the truck cycles high and low by it's self and it takes for ever to get to 65 degrees.

On a side note my compressor was making a loud rattling noise before I filled it. Now that noise is gone.

Any ideas?

Thanks
Mark
 

99KON22's

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my ac blows hot in front and cold in the back.. cant figure out whats wrong please help
 

jrsavoie

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We have several vehicles from a 1994 K3500 to a 1998 K2500 all converted to R134 a long time ago

How do we get these vehicles to blow ice cold?

We've had them to a few shops and invested quite a bit of money in them. They don't stay fixed and they haven't been ice cold in years.

I had an aftermarket AC put in a 1989 C2500 by Jack Stoltz in Springfield, Illinois in about 1991.

I don't even know if they are still there but they are about 3 hours away.

Is there a way to make these blow cold with R134?

Do to health reasons, I need cold air. For the same reason I can't afford new vehicles.

Thanks
 

SunlitComet

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Did you flush the system of old oil and refrigerant? did you change all the seals and o-rings? Replace your accumulator? Did you evacuate them really well? As long as there are no leaks R-12 is more efficient at it job then r-134a.
 
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jrsavoie

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5 vehicles total all of the vehicles were changed to R134 years ago. They've all had new pumps & filters & a lot of other stuff.

I do not do AC work myself. I have a card but for years I was on the road. So I've hired everything done. Consequently I have no idea what was done or how it was done. But It wasn't done good enough apparently

Or is it that R134 just doesn't get as cold as R12?

But the 69 had the aftermarket with R134 and it blew colder than any of the other vehicles.

Is there a way to make these vehicles cold?

Do new vehicles blow ice cold?

I need to know if these vehicles can be made ice cold with an aftermarket system or whatever or if I need to be selling stuff and buying a new vehicle.

Did you flush the system of old oil and refrigerant? did you change all the seals and o-rings? Replace your accumulator? Did you evacuate them really well? As long as there are no leaks R-12 is more efficient at it job then r-134a.
 

AtomicHoe094

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Nothing blows as cold as the older cars anymore. Its just with all the EPA, air pollutant shit going on. Both are extremely bad for the ozone but whatver
 

SunlitComet

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Like I said r-134a is not as efficient as r-12 but it can still do a good job when working properly. I would say now that you should pick with the worst performance and throw some gauges on it and see what is going on in there.
 

95TwinTT

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I like using the 30 lb bottles. It’s a lot cheaper in the long run. When my R-12 bottle ran out, I got the new “Hot Shot” R-414B. It takes the place of R-12, R-134a, R-500 and 8 other versions of Freon.

The thing to keep in mind about the various versions of Freon is that they all run at different pressures. For example, Puron, that has taken the place of R-22 in residential units, runs around 150 psi on the low side, where R-22 ran around 70 psi.

There are some new gauge sets out there that have all the various scales on them, but they are expensive. :)
 

the big blue bus

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i did my buddys truck at my tech school for 20 bucks should have done mine too before summer but im more a windows down person so its not really botherd me haha. but it would be good to know it will be really cold when i need it
 

jrsavoie

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Does R-414B get colder than R-134?

What does it take to change over from R-134 to R-414B?

Thanks

I like using the 30 lb bottles. It’s a lot cheaper in the long run. When my R-12 bottle ran out, I got the new “Hot Shot” R-414B. It takes the place of R-12, R-134a, R-500 and 8 other versions of Freon.

The thing to keep in mind about the various versions of Freon is that they all run at different pressures. For example, Puron, that has taken the place of R-22 in residential units, runs around 150 psi on the low side, where R-22 ran around 70 psi.

There are some new gauge sets out there that have all the various scales on them, but they are expensive. :)
 

95TwinTT

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Does R-414B get colder than R-134?

What does it take to change over from R-134 to R-414B?

Thanks

When I switched over, I just ran the vacuum pump on the system, and loaded the R-414B, by weight. Each vehicle has a label as to the exact amount of freon required for that system.

No other changes were done and I can’t tell the difference between the old freon versus the new.

Between myself and friends, we do enough engine mods, where the air con has to be removed during the mod, that re-charging air cons, is done often enough to make the 30 lb bottle the only sensible way to go.
 

BlkYukon95

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Hey guys, I have zero A/C experience. I got my truck in Jan and the ac has not worked. I do not hear the compressor kick in at all (which thanks to this thread tells me it may just be the safety feature that shuts it off with no freon in the system).

So where should I start to get my truck cold? What type of freon does my truck take ('95)?

Thanks!
 

jrsavoie

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Were you switching from R12 or R134?

How cold is it? Ice Cold? very cold? or just cold? What's your best guestimation?

When I switched over, I just ran the vacuum pump on the system, and loaded the R-414B, by weight. Each vehicle has a label as to the exact amount of freon required for that system.

No other changes were done and I can’t tell the difference between the old freon versus the new.

Between myself and friends, we do enough engine mods, where the air con has to be removed during the mod, that re-charging air cons, is done often enough to make the 30 lb bottle the only sensible way to go.
 

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