How to tell when A/C needs recharge?

TDIfor

Veteran Member
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Aug 20, 2003
Location
Logan, Ohio
TDI
'02 NB Double Yellow
Gentlefolk;

A GTG is happening in my area in a couple of weeks,and I have been pondering my A/C.

'02 NB 92K miles.

Bought it used when it was a year old, so Im assuming nothing has been done with the A/C. I have not touched it since I have had it.

It is blowing cool, OK, but not cold. Im wondering, if after 4 years, it may need a recharge, and if so, do I need some magical VW spec 88339495DF4377V22$$3.010002020 refridgerant?

How do I tell if the A/C is low?

How complex is the procedure for a recharge if needed?

Is this something feasible to do during a GTG?

thanks!

Don
 

cage

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Mar 25, 1999
Location
lakewood, ohio
Well here's my story...
My car was no longer blowing very cool. I bought a charging kit with gague from k-mart. Hooked it up and it said OK so I didn't add any. I then took it into the garage and told them it wasn't low so maybe the expansion valve was bad. They called me and said that they added freon and everything is good. ($80.00) If only I would have just added to begin with!
My advise... go get a kit and try adding some. If you over fill (not that I am saying you should over fill it.) but if you do there is a blow off valve on the pump that will vent excess.
Oh and yes they do lose charge over time. That's a big part of the reson cars require the newer freon. All the connections along with flex lines ect... cause leaks that home air and refrigerations units don't have.
 

TDIfor

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Location
Logan, Ohio
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'02 NB Double Yellow
Uhhh... never having tried this before... just WHAT do i get? Freon isnt used anymore, is it? And does the VW take the standard fittings that I once used on my cousin-in-law's '68 Mustang? this being the limit of my experience.

Oh,and were does stuff connect? Rather like the old Bill Cosby routine when he bought a new sports car and couldnt find the filler cap, he proposed to spray the gas all over the car and maybe it would suck in somewhere....
 

TDIfor

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'02 NB Double Yellow
Sounds right. One size fits all for the fittings? If I get a standard recharge kit from a parts store, it has the bits and pieces I need??

thx!!
 

gtveloce

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Long Beach, CA
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2003 Silver 5dr Golf TDI 5spd (RIP)
R134a system has different fittings than R12.

Part stores should sell a kit that has the R134a in a spray can like container and the hose that let you hook it up to the system.
You will see two caps inside the engine bay, one is HIGH, one is LOW - refer to the instruction manual that come with the recharge kit.
I think I paid $30 for my kit, with a pressure gauage built in. which let you check if your system is low or not, and whether you filled it up correctly.
 
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gtveloce

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2003 Silver 5dr Golf TDI 5spd (RIP)
I think the HIGH (pressure) and LOW (pressure) fittings are different too - so you won't put the recharge kit on the wrong side.
IIRC, they are industry standard size so all cars have the same size fittings (Honda, VW, Toyota, etc - as long as they are R134a)

The kit I bought had everything I needed. Just make sure to read the instructions.
 

cage

Top Post Dawg
Joined
Mar 25, 1999
Location
lakewood, ohio
Yeah I call it freon. SORRY!!!! I also call tissues Kleenex!!!! :)
One thing you won't want is the "freon" with the oil. It is the gas that escapes and the oil stays behind. Getting the one with both will lower the efficency of the system as you will then have too much oil in there.
 

cage

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Location
lakewood, ohio
If all you can find is the one with the oil it isn't the end of the world so don't kill yourself trying to find it.
 

PDJetta

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Northern Virginia
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'04 Jetta GLS TDI Pumpe Duce Platinum Grey w/ Leather
The only way to accurately charge the system is to completely evacuate the system, pull a vacuum and meter in (with an electronic referigerant scale) the exact weight of the charge. Its not a DIY job.

With that said, I bought one of those R-134a kits at the auto parts store and got a Nissan Maxima A/C system filled and blowing nice cold air again. I knew the system took 28 ounces and I put in the refrigerant until the air got cold and then a little more, about 2/3 of a 14 ounce can.

You charge from the LOW, or suction side!

--Nate
 

cage

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Mar 25, 1999
Location
lakewood, ohio
PD that's true about the accurage way but years ago I had a hose go bad on my Dodge's AC and replaced it myself. I then had a friend of a friend who was an "H.V.A.C. guy" refill it for me. I watched as he watched the gagues and weight etc then PASSSSSTTTT the compressor safety valve let loose and he stopped filling it. :) (so much for an expert doing it for you.)
I had better AC in that car than it ever did after that and I bought the car brand new.
 

rperks

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I just did this with the $20 wallmart solution, and realized what I had been missing. The AC is cold as ice again, it only took a couple of minutes. And I had thought it had been my imagination for the last 2 years that hings were getting warmer.

Rob
 

bjmarler

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Tullahoma, TN
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Jetta GLS, 2004, White
When you add the can of refrigerant, does the can sit upright, or upside down?

The reason I ask is that different products at Wal-Mart have different instructions. So, I was wondering about the "basic" can of R134, and what orientation it should be pointed while charging the system?
 

PDJetta

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You charge the system with the can UPRIGHT, engine running, A/C on High! So gas, not liquid, goes in the LOW (suction) (Larger hose) side. Charging with the can updide down can introduce liquid R-134a and lock up the compressor, ruining it:eek:

Charging on the high side can blow up the R-134a can:eek::eek::eek: I think different fittings are on the high and low side ports to prevent this. (on the old R-12 systems, they were the same fillting, so mistake could happen!)

--Nate
 

PDJetta

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It can take serval minutes for the can to empty. Warming with your hands may help. The can will get cold as the gas vaporizes in it.

--Nate
 

JoeBleed

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Charging the system way beyond what it is suppose to be charged to is not a good thing for the compressor. The emergency blow off valve will blow off only at a much higher psi than the system is suppose to contain and operate under normal circumstances. If I remember right from the Bentley it is around 200psi over normal operating conditions.

I don’t advising to charge it just because it isn’t could as you would like it. With R134a systems you should only expect the air coming from the center vents to be around 15 to 20 degrees cooler than the ambient temp. If you use a probe thermometer in the center vents and the ambient temp is around 75 degrees fahrenheit, then the air from the center vents should be around 55 degrees after about 5 minutes of operation at MAX.

A few ounces over probably will not hurt anything but too much over, in my opinion, isn’t good for the compressor and will probably give you more of a fuel mileage hit due to the compressor having to deal with a much higher operating pressure. I want to say the high-pressure side normally operates around 600+ psi. I can’t remember the numbers off hand but I read it in the Bentley a week ago.

R134a does not cool as well as R12 systems did. Even with bigger condensers. And don’t thing about converting the R134a system to R12 even if you can get your hands on it with out a license. It will damage the seals.

Good luck with checking it. :)
 

cage

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Location
lakewood, ohio
Well nobody is saying to overcharge the system. The point we are trying to make is that.
Yes, auto systems lose charge over time without there being a "problem" with the system. Rather than take it in to a garage and pay $$$$$ for them to hopefully simply re-charge the system but possibly gouge you for not needed repairs... first try an over the counter kit.
Mine is on it's second summer since the re-charge and works beautifully.
 

JoeBleed

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In post #2 you stated that you bought a kit to check yours yourself. It told you that you were OK on it. So you took it to the shop. They put more in and it worked better. I was wondering if they over charged the system or the cheap gauges from k-mart were just not right?

I didn’t want someone to take it that it was ok and a good idea to over charge the system to try and get it cooler.
 

bjmarler

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I use a probe thermometer in mine all the time to keep an eye on how the A/C is running. Typically it will cool down to about 40 F. Once in a while it will dip a little below 40 F. On a really hot day, it will only get down to about 42 F.

All that of course is with the A/C on high, and recirculate turned on.

Is that normal?
 

cage

Top Post Dawg
Joined
Mar 25, 1999
Location
lakewood, ohio
Yeah I think it was a gague issue. I mean I am looking at it right now and it doesn't point to zero it is actually almost 1/4" above zero which would put it into the charged zone when it should have been in the low zone when I checked the system.
I didn't notice that 'til now!!!!!!!!!!!!!!!!!!! If I would have noticed that 18 months ago I would have added!!!!!!!!!!!!!!!!!!! Now I'm pissed! Thanks for pointing this out to me and ruining my day! ;-)
 

cage

Top Post Dawg
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Mar 25, 1999
Location
lakewood, ohio
I just took the face off of the gague and moved the needle tward zero and the little gear inside jumped a tooth and now it points to zero! That's all that was wrong is the needle was off one tooth.
 

TDIfor

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Aug 20, 2003
Location
Logan, Ohio
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'02 NB Double Yellow
OK, thanks, all. Ive opted for a $27 Auto Zone solution that includes an $18 guage and a $9 can of generic R134. Oh, and thanks for the tip about not inverting the can.. was kinda wondering about that, owing the wealth of room I have in an NB....

Reason for this is the AC is just not cooling the cabin. Not a matter of not as cool as I would like, but a matter of cooling sufficiently. Cooling has fallen off considerably since last summer, even tho I did cycle the AC on several times during the winter.

So, one will hope I dont muck anything up. And if I can't get a success here, Im out $27. I can absorb that.

Off to peer at my NB now!
 

PDJetta

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'04 Jetta GLS TDI Pumpe Duce Platinum Grey w/ Leather
You may have a refrigerant leak. While you are under the hood, look for slightly oil areas on the A/C system. (oil is mixed with the refrigerant when the system runs. If there is a refrigerant leak, there will be oil left behind). Pay particular attention to A/C hose connections, the compressor seal area (behind the pulley) and the condenser front (a rock may have punctured it). The condenser sits in front of the radiator. If a hose fitting is a little oily, snug it a little tighter, using a wrench(es).

--Nate
 
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