AC dryer now a maintenance item?

[Astro14]

Weren't they always considered a "maintenance item"?

IIRC, one shop manger refered to it doing a job similiar to what an oil filter does for an engine.

I don’t think so… In some of my cars, the whole front bumper has to come off to get at it. That’s not a maintenance item, but more of a “fix when broken” thing…

 

[Kurtatron]

This is seems so contradictory given that oems have “lifetime” fluids for transmissions. Why do they care so much for the AC but not the transmissions?

 

[Avery4]

This is seems so contradictory given that oems have “lifetime” fluids for transmissions. Why do they care so much for the AC but not the transmissions?

From my understanding, in the case of EV's, the AC system is often used for helping to cool and sometimes heat the battery and possibly other components such as inverters and motors. So since the performance of the AC system is important to the functionality of EV's, the manufacturer likely considers maintaining it more of a priority.

That would not, however, explain why some combustion vehicles are also requiring scheduled dryer replacements and neither would the electric compressor theory.

 

[brianl703]

Just a guess, but electric vehicles have air conditioning compressors that are ran by an electric motor. And the electric motor has wires with varnish. If over time some of that varnish were to get into the oil and refrigerant then it could find its way to the desiccant in the dryer. After a while it could clog the dryer up enough that the air conditioning system would stop working.

That doesn't seem to be a problem with compressors for stationary AC/refrigeration applications, some of which go decades without any repairs (other than capacitor and contactor replacements).

 

[Avery4]

That doesn't seem to be a problem with compressors for stationary AC/refrigeration applications, some of which go decades without any repairs (other than capacitor and contactor replacements).

I was just about to say that. No one even thinks about changing the dryer in their refrigerator or central AC unit and they are normally brazed in with no way to easily replace them, yet they still almost always last for the life of the system.

And although contamination may be more of a problem in electric AC compressors and should be avoided at all costs, I'm not sure they are actually as sensitive as manufacturers want us to believe considering the fact that HVAC techs very often aren't nearly as careful as they should be about avoiding contamination, yet central AC systems seem to last decades anyways.

 

[Oillover]

I don’t think so… In some of my cars, the whole front bumper has to come off to get at it. That’s not a maintenance item, but more of a “fix when broken” thing…

I agree, but the way it was explained to me.
Made me think it was something that should be replaced with time (to keep the system operating efficiently).

 

[another Todd]

Weren't they always considered a "maintenance item"?

IIRC, one shop manger refered to it doing a job similiar to what an oil filter does for an engine.

Except that it is a sealed system, no additional moisture is introduced after charging it up, and if there are enough wear particles to plug it up, then you have other signs of system failure.

 

[JimPghPA]

That doesn't seem to be a problem with compressors for stationary AC/refrigeration applications, some of which go decades without any repairs (other than capacitor and contactor replacements).

Good point. I should have thought of that. Although the only thing that I know maybe different as far as a residential sealed AC system and an electric vehicle sealed AC system is that it is my understanding from what I have read that the voltages that are used in electric vehicles for the AC system are very high. I would also suspect that to some extent they may have a variable frequency to vary the speed of the compressor but I do not know if that is the case. Still in all, you may be absolutely correct that the refrigerant and its oils flowing in contact with the electric motor may not be any concern whatsoever.

So I guess the final question is, is this just a dealer rip off? Or is this a legitimate maintenance concern? Let's approach this from a purely scientific view of what's going on. I'll keep an eye on this thread and hope that somebody else with more knowledge than I have chimes in about any reasons that there could be or should not be changing of that dryer, filter, accumulator.

 

[brianl703]

Good point. I should have thought of that. Although the only thing that I know maybe different as far as a residential sealed AC system and an electric vehicle sealed AC system is that it is my understanding from what I have read that the voltages that are used in electric vehicles for the AC system are very high.

Commercial sealed AC systems often use 480V 3-phase. Even the small ones like a 2-ton split unit (otherwise the same as might be used in a residential system) are available in that voltage. 480V is probably higher than most EVs use for their compressors.

 

[Chris142]

In ac class we are told that the dryer should be replaced every 5 years or so. Nobody ever does that.

I do believe in evacuating the system. Pulling a good vacuum,adding oil if needed and recharging it about that often.

 

[JHZR2]

lol, I didn’t think Teslas needed maintenance.

If the pressure is lost, sure. Otherwise I have 30yr old units in service with perfect cooling and minimal loss.

Seriously though, I suspect it has something to do with electrified auxiliary systems.

 

[97prizm]

What's up with AC accumulator/receiver dryers now apparently being a maintenance item? Now we have Tesla requiring a replacement every 2-6 years depending on the model, GM requiring a replacement every 7 years on at least one model (the Traverse), Delphi recommending a replacement every 2 years, and Valeo recommending a replacement every 3 years. What is this about? I never even heard of replacing AC dryers preventatively until a friend with a Tesla told me that he had to have his replaced and I thought the dealer scammed him until I did some research and saw that's actually a thing now.

I can only think of two possible theories for why this might be. Either the new R1234YF refrigerant or its oil is degrading the desiccant or there has been a major change in the way they are being made, although neither theory makes much sense. Does anyone have any other ideas on why AC dryers apparently have to be replaced as part of scheduled maintenance now?


https://www.tesla.com/support/vehicle-maintenance

https://cdn.dealereprocess.org/cdn/servicemanuals/chevrolet/2019-traverse.pdf (page 371)

https://www.delphiautoparts.com/en-...rier should be,drier should also be replaced.

https://www.valeoservice.com/en-com...nditioning-spare-parts/receiver-dryer-car-air

The Tesla requiring this doesn't shock me. My 1997 geo nor my 2005 Dodge Neon I don't think mention this as a requirement.

 

[wtd]

The only time I replace the dryer/accumulator is if I am replacing some component in the system or have the system open for any length of time. I'm definitely not opening up a perfectly fine running system periodically to replace one.