A/C Desiccant

A/C Desiccant

Bringing my 6/2017 75D with 49,879 miles on Thursday for brake fluid flush, caliper cleaning and lube, screen yellow band treatment. They recommended the full 2 yr service which includes the A/C desiccant.

I usually do things a la carte, but is the A/C service necessary ? How long will it actually last ? Could there be damage if not serviced ? Should I just wait until A/C just stops working and then service ?

I live in NY. Thanks.

mizunosan | 13. marraskuu 2019

Do you have the Bio Weapons mode in your car? If so, the desiccant and filters should be changed as they can start to build up with dust and desiccant may be less effective as it absorbs moisture over the past 2 years.

jordanrichard | 13. marraskuu 2019

Well, you can wait until a hot summer's day to then find out your AC is not working properly.

cfishkin01 | 25. marraskuu 2019

I was going to take your advice, lol, but I was quoted $200 so I told them to do it. Went to pickup the car, and they had forgotten to do it, so the service advisor gave me the same advice you did. They also could not treat the yellow band since the machine was broken. Said to come back in 2 weeks. They also said they checked the brake fluid and calipers and no service needed. I'll try again in a year.

Daisy the Road ... | 26. marraskuu 2019

Isn't the AC system entirely sealed and pressurized? The dessicant is there to remove moisture that enters when the system is filled. The only way to replace it is to open up the system, which turns into a chicken-n-egg situation.

redacted | 26. marraskuu 2019

I can't imagine desiccant dehumidifying air in the cabin of a period of years. if it does, I'll just buy that instead of paying for a dehumidifier | 26. marraskuu 2019

@Daisy the Road - I believe the A/C system is depressurized and drained (actually saved), then the when empty, the desiccant is replaced and the system refilled and pressurized. It seems like a common procedure on all cars with HVAC systems. Nothing particularly unique about Tesla in this regard.

I'm not a mechanic and have never done the process myself, so perhaps someone else who has done it can chime in if I don't have it quite right. | 26. marraskuu 2019

@redacted - It's only for the HVAC coolant. It is not used for the cabin air.

cfishkin01 | 26. marraskuu 2019

Something else curious. Recommended replacement times:

Model S: 2 years
Model X: 4 years
Model 3: 6 years