The climate is no longer cooling as it did in the beginning

Yes, my air conditioning isn't cooling as well as it did on the first day we got the car. However, it was only refilled last week, and even then, it wasn't working exceptionally well. What could that be?

Best regards, WarLord.

Hello,

Was the filter dryer also replaced?

Who is responsible for removing moisture from the coolant? No, nothing was exchanged; only the old coolant was drained, and the new coolant was added.

Best regards, WarLord.

Hi,

Try taking pressure measurements on-site; the newer ones even have sensors that you can query.
(A4 130PD 2001)

If the amount of coolant is correct, it should reach the normal pressure (e.g., 20 bar) within a certain time; otherwise, you may have a problem. Then, it might be the compressor.

If he doesn't achieve that, and you want to replace the compressor, the refrigerant will have to be drained anyway. At that point, you can re-check to see if there was enough refrigerant, or if it's leaking.
By the way, apparently very few workshops have the equipment for this. If not, you'll need to go to a company that specializes in refrigeration systems. They are also cheaper than car repair shops or ATU.

My A4 was practically empty after 4 years, and we only ever refilled it. (I refilled the Audi at a Daimler station!!!) Now I'm getting that feeling again...

Hello,

The filter dryer is not only responsible for the water. It also filters out impurities (especially those from the refrigerant oil) and neutralizes the acids that are formed.
When refilling an air conditioning system, a reputable workshop will always replace the filter dryer.
You can compare it to changing the oil: You wouldn't just change the oil and leave the old filter in, would you?

Does the new filter dryer actually work?

@garth.brooks

Where can I find the standard pressure for my system? The HVAC technician had a pressure gauge and said the system wasn't performing optimally. But that can't be right, because last year my local mechanic refilled it, and it was working great then. The cooling performance hasn't really decreased this year, and then suddenly it stopped working. Nothing more from the system.

Best regards, WarLord.

Regarding filter dryers:

In golf cartridges, the filter drier has a water and acid absorption capacity of approximately 8 grams.
The actual filter consists of a plastic container filled with loose granules, which are enclosed above and below by a filter fleece. The entire flow rate passes through the filter element. Unlike pressed granules, a significant portion of the foreign particle filtration is not performed within the loose granules, but exclusively by the filter fleece. With each filling, a certain amount of water and additional foreign particles are introduced into the system. Normal operation will inevitably result in a certain level of contamination (compressor).
That's the reason why you should always replace both the dryer drum and the heating element at the same time.

The problem you're experiencing might not be caused solely by the dryer. Ideally (as mentioned above), have a pressure measurement taken on both the high-pressure and low-pressure sides.

Here's the translation:

"By the way, was the necessary amount of refrigerant oil also added during the refill?"

No, and the refrigeration specialist, the man from VW, and another mechanic from Bosch believe that it's not necessary if you're simply replacing the coolant.

Best regards, WarLord.

Hello,

The problem is that these "rudimentary" filling methods always allow some cold oil to escape from the system.
Then, it's likely that a pressure test (which is actually required after filling a VAG system) wasn't performed either?
Did you notice how much they filled it with?

'No, unfortunately not. They filled it using a pressure gauge. Then I started the machine, and the guy watched the readings on the gauge. After that, he said the system wasn't in the best condition anymore.' Do you mean that there are still too few resources available in the system?

Best regards, WarLord.

Hello,

Have you perhaps noticed where they connected the pressure gauge?
Did they use one or two pressure gauges?

A pressure gauge with a section for high pressure and a section for low pressure. The technician had connected it to the corresponding ports (as far as I could tell). Then, he opened both valves. Next, he evacuated the old refrigerant (using a pump connected to the lower part of the pressure gauge) and then connected the hose from where the pump was connected to the cylinder containing the refrigerant. He then opened the cylinder valve and then the valve on the pressure gauge. After that, we heard the refrigerant flowing into the lines. He then said, while it was still hissing, that I should start the car. I did it, and it came out cold, not as strong as I expected, but still cold.

Best regards, WarLord.

Hello,

Let me see if I can find the pressure values for your system.
What kind of vehicle is it?

VW Passat 35i facelift, manufactured in 1996 (as far as I know), with a 1Z engine.

Best regards, WarLord.

Hello,

First, the filling volumes:

R134a: 1150 + 50 grams.
Refrigerant oil: 115 ccm.

Do the 115 cc need to be purged every time the refrigerant is filled, or is that the total amount of refrigerant that is present in the system?

Best regards, WarLord.