AC Question

Joined
May 25, 2005
Messages
15,205
Location
ROCHESTER, NY
My Altima in signature has an AC refrigerant leak. I’ve topped it off 2X recently.
When using a gas sniffer, is the sniffer detecting the refrigerant or the dye?
I went to a shop today to make an appt to check my system and through our discussion, the tech told my that they don’t use a gas leak detector(sniffer/snake) any longer.

They evacuate the system, recharge it through the manifold gauges and search for the leak/issue and repair. Yes, the also pull vacuum after the complete repair. .

But my Q is about the sniffer. Is it sniffing for a R134a leak or the dye?
 
Why are you bothering to fix AC in upstate NY in late September?

It is snowing, snow falls on your head while you are clearing the car windshield. You get in the car and your head quickly turns all that snow to water vapor which then condenses on the cold glass. You need dry / hot air to clear the inside of the windshield quickly; the heater hots it, the A/C dries it.
 
It is snowing, snow falls on your head while you are clearing the car windshield. You get in the car and your head quickly turns all that snow to water vapor which then condenses on the cold glass. You need dry / hot air to clear the inside of the windshield quickly; the heater hots it, the A/C dries it.

Or you can be like the school bus drivers I remember who had a roll of paper towels to wipe the inside windshield, because those buses had no AC.
 
Or you can be like the school bus drivers I remember who had a roll of paper towels to wipe the inside windshield, because those buses had no AC.

Yup and 50 huffing and puffing schoolchildren make a lot of moisture.

FYI: my elementary school bus driver was named Karen; she was a dirty blond haired woman who wore denim overalls; cool as a cukecumber.
 
Why are you bothering to fix AC in upstate NY in late September?
It is snowing, snow falls on your head while you are clearing the car windshield. You get in the car and your head quickly turns all that snow to water vapor which then condenses on the cold glass. You need dry / hot air to clear the inside of the windshield quickly; the heater hots it, the A/C dries it.
AC helps to dehumidify the inside of the cabin and keep the windows clear(er) on those damp, snowy, cold rainy, slushy days when it sucks to have to be driving in that mess.

When you turn on your defrost or heat/defrost, the AC compressor kicks on to aid in the clearing of the windows.
zzyzzx: AC isn’t just for the hot/humid summer days…that’s why! ;)

Also, when an AC compressor is idle/still all winter long(as in the past- 30 plus yrs ago), compressors had/have a higher failure rate. And most people didn’t turn on the AC in the winter because they just didn’t know.
Compressors need to run periodically.
 
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It sniffs for R134a.

Canned air (R152a) will also set it off, and is a good way to test a sniffer for correct operation.
Thank you Brian.
This confirms my notion that the guy/shop that I took my Altima to(just too make an appt.), who also stated that the air conditioning DOES NOT contribute to better Defrost/Defog(mainly interior defog) performance in the winter time IS NOT the person/shop that I should be taking my car to for AC maintenance/repairs. This guy also stated that the "leak detectors"(sniffer/snake) in which they do not use any longer..."DOES NOT sniff for refrigerant leaks, it sniffs for the dye"...WHAAAAT?

The leak detector(sniffer/snake) sniffs for refrigerant/gas/fuels/natural gas in homes etc. And the dye is for the visual in finding exactly where the leak is by eye and/or with UV light.
 
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Thank you Brian.
This confirms my notion that the guy/shop that I took my Altima to(just too make an appt.), who also stated that the air conditioning DOES NOT contribute to better Defrost/Defog performance in the winter time is not the person/shop that I should be taking my car to for AC maintenance/repairs. He also stated that the "leak detectors"(sniffer/snake) DOES NOT sniff for refrigerant leaks, it sniffs for the dye...WHAAAAT?
(y) Your confirmation is correct, it's time for another shop.
 
Why are you bothering to fix AC in upstate NY in late September?
So that the defroster works properly clearing the inside of the windshield in the high humidity of a snowstorm, where the windshield is cold and condenses moisture on the inside.

Sorry, missed all the replies saying the same. If you’ve lived where it snows a lot, you already know why…
 
Even though that guy you spoke with at the shop was wrong about the need for AC and what the sniffer detects, I can see why he doesn't use them - they (mine at least) don't seem to work very well at times. Not sure why? It'll detect bigger leaks, but just doesn't pick up smaller leaks that I might otherwise be able to see with UV dye and black light




Yup and 50 huffing and puffing schoolchildren make a lot of moisture.

FYI: my elementary school bus driver was named Karen; she was a dirty blond haired woman who wore denim overalls; cool as a cukecumber.

Mine was named Rose - a little sawed off gal, but man was she hard charging, gear jamming driver! Just about every day she'd give that International engine and 5 speed a thrashing 😂. And man was she good with the 2 speed rear! Way better than I am...
 
Sorry if I'm hijacking, but this post got me thinking...is there really any type of PM to do on an A/C system?
 
When you turn on your defrost or heat/defrost, the AC compressor kicks on to aid in the clearing of the windows.
zzyzzx: AC isn’t just for the hot/humid summer days…that’s why! ;)
Maybe late model cars are different, but I was always told the compressor doesn't kick in at low temperatures like below 50F or 40F as the oil is thick and could damage it.
 
Maybe late model cars are different, but I was always told the compressor doesn't kick in at low temperatures like below 50F or 40F as the oil is thick and could damage it.

It'll kick in as long as the evaporator temperature isn't below 32F, or some slightly higher temperature. This is controlled either by a low pressure side switch, an evaporator temperature sensor, or both.
 
Leaks.... you have a "Leak". Regardless of how you detect it, you must find it and then repair it. Best bet is to find a good shop to determine the source and go from there.
 
Since dye rides in the oil, dye only comes out of leaks while the system is charged up and running. When it is stopped, the dye-laden oil sits still and unless the leak is under a pool of oil, it won't come out, only gas will. So sniffers are very useful for leak checking.
 
The refrigerant leak detector ( sniffer) finds leaks by sniffing refrigerant. The ac dye is used with a special light and yellow colored glasses

I personally have not had much luck with sniffers. The dye works much better for me.

Since it's an Altima it needs a hose. Seems like they all did! Look for an oil soaked hose.
 
^^^ I’ve been looking and I am just not seeing anything.
I think I saw a little oil on one line as I was under the car doing an OCI yesterday but I’m just not sure.
I wiped it clean and I’ll check again in a few days.
 
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