Transmission flush

But I seem to have lines running back to the transmission from that area

 

03/18

 

Well isn't that the strangest thing. It does indeed look like you have the trans cooler and running the R1234YF in the old AC exchanger. I was expecting a late build 2018. How well does the AC cool?

Here is a picture of my 2016 and you can see it's the same as yours and it's using R134A.


I use to own a 2020 and I'll see if I can dig up a picture of the R1234YF condenser.

 

You are mistaken. 2018 was the first year for R1234yf but still had a transmission cooler. It is believed that due to complaints about less efficient cooling with the new refrigerant caused them to redesign the condenser thus eliminating the transmission cooler.

 

Yes we have established that he already has the ambient transmission cooler. I did not know that Toyota tried using R1234YF in the 2018 rather than redesigning it.

 

So I've only owned the truck since December and it's been generally cool here (I live in Prescott, AZ - elevation about 5300ft), so I haven't really needed the AC. But just this past week we've had some highs around 65°F, and I turned the AC on and needed nearly full blast on the lowest temperature setting just to be comfortable. So I'm worried about it come summer time to be honest. It will reach highs of around 100°F for a few weeks in the summer here.

Theoretically would it be possible to have an AC shop remove the R-1234YF and recharge the system back up with R134 if it's just not adequately cooling come summer time?

 

I was just thinking the same thing. The AC ports are different between the R134a and R1234YF so switching refrigerant would require a port change so the R134a machine could be connected. The port is part of the hose so you would probably have to change the hoses unless you can find a AC shop that has adaptors.

Here is what the R134a port looks like.

 

I may have to find a local AC shop and ask them. Them having an adapter sure would be nicer than having to change the hoses out. May make a thread on here to ask other 2018 owners if anyone's already looked into this. I hope I'm just wrong and come summer it's adequate, but I'm already one of those guys who runs hot all the time, so I kinda doubt it.

 

Based on the fact that they changed the design in 2019 I'm guessing you may find it inadequate. On my 2016 the AC is colder than my previous 2020 with the R1234YF and new design. I've had both trucks in the heat of Florida and the 2016 is on never on max in 95° heat. I couldn't see how the old design meant for R134A would work well with the new refrigerant.

 

Haha. I called the local dealer. They don’t carry the drain. And won’t give the part number.

 

You got a bad parts guy. At the dealership we had those in stock and we changed them out every trans service.

 

A quick search

$8 35178-30010 luxlead 20 PCS Transmission Drain Plug Gaskets Oil Crush Washer Seal Rings Compatible with Toyota Lexus 4Runner Sequoia Tacoma Tundra Lexus GS450H, IS250/350, LS430, LS460, Replaces 35178-30010

35178-30010

 

Same picture I found too. Thank you. They are the same gasket.

 

Yea I kinda figured that too. Going to start doing research on the freon swap, and see where that gets me. I bought this truck and upgraded from daily driving my '03 Tacoma, and definitely didn't expect to be less comfortable come summer time lol

 

Look what I found.
https://www.ebay.com/itm/3749464659...B6BtnRzT1a&var=&widget_ver=artemis&media=COPY

 

Very nice. Ordering now!

Now should I look to doing this myself? I had a friend bring up the fact that an actual AC shop might consider removing the newer eco-friendly refrigerant and substituting it with R134A illegal. Any truth to that?

 

You won't be able to do it yourself. To do AC, after removing the refrigerant the system has to brought to a vacuum for approx 15min to remove any moisture then a precise amount of refrigerant is added and the gauges have to me checked to make sure the system is operating properly. Your friend is probably right about it being illegal. I would just find a small independent garage or mobile service to do the work. Install your adaptors and tell them it's a 2017 and use R134.

 

And I should probably remove my R-1234yf sticker too I'm sure. Thank you for all the tips.

 

I was doing a little research because I was curious. From the info I've come across the refrigerant oil that is used in R1234YF is not compatible with the R134A so you will have to have the system flushed to remove the old oil them add the correct amount of PAG oil them recharge with R134A. Easy enough but an important step.

Here is a good read.
https://www.quora.com/Can-1234YF-fr...ues-for-the-car-s-air-conditioning-compressor

 

Could you folks clarify something for me: when you say do 2-3 drain and fill do you mean drain it wait a certain time or milage and then drain and fill again? If so what is the recommended time or milage in between? Also I've read that it take about 4 quarts of WS each drain and fill?

Thanks in advance.
Edsel

 

I do a drain and fill every 30k

valvoline maxlife

 

Some people will say to do 2-3 drain and fills if you are looking to exchange more fluid because the entire system is around 12qts so doing one only replaces a 3rd of the fluid. Personally I just do a drain and fill of 4qts around 15-20k miles to keep the fluid fresh. Theres no real right or wrong here, Toyota only suggests a drain and fill at 60k. The whole thing is just to not wait long enough that you are in that position that having dirty fluid is what your transmission is relying on to not slip, thats when the experts suggest to just ride it out and not replace it. Keeping it fresh with some drain and fills every now and again seems to be the best option.

 

I'm at 103K milage. Hopefully I don't have the dirty fluid that the transmission is relying on. Yikes

 

I would do one drain and fill then let it ride for 15-20k like Joe mentioned. I think you'll be just fine. I did a full DIY flush at 92k miles (first service it's ever had that I'm aware of) and and I've worked the truck hard since then with thousands of miles of heavy towing, and it's been just fine.

I wouldn't think too much about it. Just drain, fill, come back in a year or two.

 

I overhauled fully 1 car HVAC system (so I must be a pro, he-he) and I'm not sure all of PAG can be cleaned out. There's a lot of oil in condenser, evaporator, compressor and dryer. Even tubes have a thin layer of oil. Vacuum pump does not evacuate any oil, only gas.

If the performance of AC is an issue, I'd invest into a water mist sprayer system. It improves heat exchange a lot. Lot more than a successful R134a conversion can do. Good for engine and transmission cooling, too.

 

I see what you're saying, but if the pre-2018 trucks used R134a in the same AC condenser (that doubles as a transmission cooler), and their AC performance is better (some may even say way better) then, that seems the easier and more convenient solution, compared to a water mist sprayer system.

 

Mixing incompatible fluids is never easier.

 

Fair point. I think I need to make a dedicated thread to this topic and see if any other 2018 owners have done anything about this, besides living with substandard AC.

I wonder if I could reroute my transmission cooler lines and bypass the AC condenser, and send them to a standalone cooler. Then in theory the AC system may become adequate without it soaking up heat from the transmission. No 2019+ owners gripe about their AC right?

 

It's OK if you don't clean out all of the oil that is used with the R1234YF. R134A uses a PAG oil and it can be carried by the refrigerant but the oil used by R1234YF (glycol lubricant) cannot mix with R134A. If the correct amount of PAG oil is used the small amount of the glycol based oil left in the system after the flush won't harm the compressor.

The only negative leaving some of the glycol based oil in is that is will slightly reduce the efficiency of the AC but it would be negligible. The same result if you add too much refrigerant oil in a system you're servicing.

 

I think your better off just changing the refrigerant to R134A. Cheaper and easier and your results would be better.