AC Dryer: How to Fill with Oil?

Hello,

Approximately 4 weeks ago, I converted the manual air conditioning system in my Golf III (built in 1997) with an AFN engine to Climatronic. To do this, it was necessary to have the refrigerant extracted so that the climate control unit could be replaced. So far, so good. Today, I received a new dryer from E*** and immediately wanted to install it. The seals for the lines that I bought from VW didn't fit; great! Full of hope, I drove to the nearest ATU service center to buy the correct seals and have the system filled. Unfortunately, they didn't have time today.

OK,

However, the master technician from ATU told me that the dryer needs to be filled with oil. Apparently, this requires removing the dryer, turning it upside down, and filling it with oil?!?!?

To the best of my knowledge, 80% of the air conditioner's oil is inside the compressor, while the rest circulates in the pipes and elsewhere.

Okay, so what's the right way to do this? In my opinion, you shouldn't need to add any oil to the dryer because R134a already has lubricating properties, right?! Besides, wouldn't it be easier to just put the oil into the regular filling ports instead of having to take the dryer out, turn it around, and then fill it?

I am confused and would like an answer.

Best regards,
Achim

However, the master technician from ATU told me that the dryer needs to be filled with oil. Apparently, this requires removing the dryer, turning it upside down, and filling it with oil?!?!?


I've never heard of that before, or done anything like it.

If the system is filled with refrigerant after installation, oil will inevitably enter the circuit along with the refrigerant.

You should install the dryer shortly before you plan to fill it.

Hello,

It's hard to believe, but today things were back to normal at ATU. Apparently, they suddenly realized overnight that the filling system automatically mixes the oil with the refrigerant.

Apparently, there are price differences depending on whether the system is empty or still contains refrigerant. In my case, it was supposed to cost €97 because it would be an empty system, which is more expensive. No one could explain why. However, I managed to get it included in a regular AC service at a price of €77.

Well, now the refrigerant is refilled .

Best regards,
Achim

Hello...

I strongly advise against adding any extra oil to the compressor.
There is a risk of overfilling, which could cause some of the oil to enter the compressor chambers in liquid form, inevitably damaging the valves.

I would strongly advise against opening the refrigerant circuit. The silica gel in the dryer is hygroscopic; once it comes into contact with air, it will absorb moisture from it.
Since the silicate can only absorb approximately 6-12 grams of moisture, it will become saturated very quickly. At that point, it will no longer be able to absorb any further moisture, even if some is present within the system.
So bleibt dann nur noch die Frage was in puncto Zerstörung schneller ist? Oil or water...?

best regards
Steve.