1234YF Refrigerant Leak - 2017 OR

Aloha,

An auto AC shop recharged my ac about a year ago. The technician used one of those gas sniffers but it didn't go off at anywhere he checked including at the ac vents. He said that it's probably a leakage at the evaporator. I come across a few post that some had their evaporator replaced. I bought my own gas (halogen) sniffer and couldn't confirm
About a year ago, I had my truck AC recharged at an auto shop. The technician used a gas sniffer, but it didn't detect any leaks, even at the AC vents. He suggested there might be a leak at the evaporator. After reading some posts online, it seems others have had their evaporators replaced.

I purchased my own halogen gas sniffer and couldn't confirm if there's a leak at the evaporator. However, I did find a leak near the low-pressure line at the firewall, possibly where it connects to the expansion valve. I found out I have a bumper-to-bumper warranty from the Toyota dealer, but it doesn't cover wear and tear repairs or parts replacement. I've scheduled an appointment with the dealer to diagnose if the warranty will cover any needed repairs or parts.

While I'm certain there's a leak on the low-pressure line, I'm unsure about the evaporator. I suspect there might be an issue with the oil ring at the connection between the metal hose and the expansion valve, which may need replacing. As for the evaporator, I'm not sure how the Toyota service technician will determine if there's a leak, given its location in the dash.

If the technician finds that the leak is only at the low-pressure lines and the oil ring needs replacement, I'm concerned it won't be covered under the warranty due to it being considered wear and tear. I'm curious if anyone else has experienced a similar issue, particularly with the oil ring wearing out, and if their bumper-to-bumper warranty covered it. My truck has only 11,000 miles on it.

 

Bumper to bumper warranty will cover this however, a 2017 shouldn't have bumper to bumper coverage. The extended warranty you have, I suspect is a third party warranty so you'd have to read into their program or wait for the diag to know. If you sniffed a leak at that txv seal then hope thats it and stop praying for an Evaporator leak.. take the easy win and run.

For your curiosity, if you don't sniff an Evaporator leak from the vents then the drain tube would be the other place to look. I've also had luck by running a borescope in the hvac box with the blower motor removed and looking at the evaporator for signs of leakage like dust sticking to oil. Alternatives to a sniffer would also be to charge the system with 1/4 Oz. Of dye added to the charge and looking for leaks with a UV light and yellow glasses. The least common in automotive land but my favourite is to leak test the old fashion way of charging the system with nitrogen and spraying things with soapy water and looking for bubbles. Even if the system is fully charged and it's hot outside the static pressure is usually high enough to soap water test it like that.

 

Mahalo for your input. I never thought of any use of a boroscope but I can see its value in looking at the evaporator from going in where the blower was mounted when removed.

I did not pick up any gas with the sniffer at the end of the drain tube. I think what will happen with the service tech is that they will just address the leakage near the expansion valve and then its a wait and see if there is still a leak as I don't see any leak or detect any leak anywhere in the engine area.

 

Sometimes thats how it is and it sucks because not all places have nitrogen to leak test so they either have to use a sniffer or recharge it and ad dye then wait for it to leak out again. R1234yf is expensive too. Another possible spot to check is the pressure relief valve at the back of the compressor. R1234yf doesn't transfer heat well so i've also seen them vent out the back of the compressor when they're running at idle with a full charge and the pressures are high... it's the nature of this refrigerant.

It's not legal down there and so this is just food for though but I do support hydrocarbon refrigerants like Duracool for reasons like that.. biggest issue is shops wouldn't want to touch it if you use Duracool or the likes.

 

if you got the Toyota extended warranty for 8 years or more then you should be good.
if no extended warranty then no.