why so many A/C’s blowing up now?

This is my philosophy. Other than checking the Freon levels, there’s nothing requiring regular maintenance. And when you live in the south, you know as soon as your BTUs start dropping. So if it doesn’t feel off, worry about something else. Like frame rust...

 

But not really. The system is always under pressure with it shut off or operating, even the low side, so unless those water molecules can swim upstream like salmon it ain't happening. There are certainly some contaminants generated by wear, and maybe from the effects of heat on the oil, refrigerant, hoses, and other parts but the only real opportunity for moisture to get in there is with an open/empty system prior to the evacuation and charge process. That's why they always tell you to replace the receiver/drier whenever the system gets opened. Unfortunately for us that also means the condenser. And that's why a really good leak test and deep evacuation are key to longevity. One of Toyota's few questionable design moves. Although they might say that this eliminates some extra lines and seals that could develop leaks.

 

Yeah, they ran the suction pump for about an hour to evacuate all air, water, refrigerant, and oil. It was the deluxe job.

 

Well they can the AC runs on defrost.

 

Face it, many of our Tacomas are just getting old.

 

I have no problem with my truck getting old...it's me getting old that's annoying. Trucks are fairly easy to fix...old, decrepit bodies aren't.

 

I never knew/noticed that the Toyota systems didn't have the receiver/drier as a separately replaceable component. That's beyond questionable: it's ridiculous (IMO) No reason it has to be part of the of the condenser. Every automotive a/c system I have had in a vehicle since the '60s has had a separate rec/drier setup. Definitely GM, Ford, Volvo (GM components after 1992), Chrysler. I'm talking way back to the "site glass" days. Cannot speak to other euro or asian systems.

One side benefit of the move to R134 as a refrigerant (other than being more friendly to the Ozone layer) was that although it was less efficient than R12, it is a much smaller molecule so required a much more robust system to hold the refrigerant: seals, fittings, compressor, etc. I have had about a 50/50 split in vehicles over the years now between R12 and R134 based systems. The R12 systems seemed to always need a charge, and the fittings, compressor and connections frequently developed a visible oil film around them from leakage.

 

I feel you. I am in the same boat. Or sinking ship!

 

I still have a can of R12 in my garage. Bought it maybe in 1982 or so for a Firebird and it traveled with me wherever I moved. Had others but this one was left over.

 

that also annoyed me. I would rather swap out the receiver/dryer than deal with the entire condenser assembly. I suspect I have a leak on the low side hose pipe and once summer passes here in FL I plan on replacing it, the seals, the condenser, and the little filter thing in the system.

 

Thank you.! It sure annoyed the heck out of me too and my a/c is working fine right now: ice cold in New England (!) of all places where we just had a heat wave of ten days over 90 degrees. Nothing like you poor so-and-so's have in the Southwest, but major up here. I'm fishing in Maine and it's the same thing: icy cold streams??? nah: Wade right in. West Branch Penobscot River. Makes me nervous: and the fish are either hiding or gone.

 

Hearing this annoyed me, too. Understatement. Makes it even more critical to do a perfect leak check and evacuation and to make sure it can hold that vacuum without dropping for awhile before charging.

 

1. 480,000 miles later and I've never touched anything in the A/C system. Still blows cold. A few years ago I asked a friend of mine who is a career mechanic if it was OK to "re-charge" the system. He said "no, the system is sealed and anytime you open up the system you invite problems. If it's still blowing cold air, leave well enough alone."

 

While this is true, unless you live in a place that stays really warm in the winter, the AC will maybe only actually be on for 2-3% of the time you drive in the winter. The evaporator will freeze up otherwise, so the AC will kick on and drop that Evaporator down to 30° and then wait for it to warm up.

In the summer, especially when it's over 110°, your compressor might kick on 100% of the time, and stay on for a number of hours at a time, which is a lot of heat and stress for the system.

 

As long as we’re on the AC subject, are these compressors a bit aggressive when they kick in? I can slightly feel a tiny lag in power while cruising when it kicks on. Also at stop lights the truck actually surges forward on the brakes.

 

I don't have an auto, so I can't say what it does to idle engine power, but it sounds pretty normal. Mine surges pretty hard when it kicks in or out, and I certainly feel it if I'm going up a steep hill, and it has scared the crap out of me having it kick in while going up a stupid steep dirt mountain side in 4LO. I thought I broke an axle or driveshaft for a second, then I realized what it was and was able to let my seat back to it's normal place by releasing the pucker...

It can, and usually does, require quite a bit of torque to move the freon through the system, especially with a piston style compressor. At least we have big heavy rotating assemblies to soak up some of the sudden torque shift, some Subarus feel like they're gonna stall for a second when the compressor on those kick in. D: Oh, yeah, I had a lightweight flywheel in my WRX, which made it even worse. Hah.

 

That's why a lot of luxury cars use a variable displacement compressor to minimize rpm changes at idle, no cycling on/off

In regards to OP's question, compressors fail fairly often because they're the ones doing all the heavy lifting in the system. And the most dependent on lubrication. If a leak develops somewhere often the compressor oil goes out the hole with the refrigerant putting the compressor at risk.

I've done a ton on lots of different cars. Honda CR-V for some reason and lots of domestic vehicles like GM and Ford

 

Fantastic long service for an A/C system. That has to be or be close to a record. I totally agree. Don't touch it unless you have a problem. I don't even put the gauges on mine to avoid cycling and wearing the schraeder valves. Those readings do not really tell you much about determining the precise state of charge anyway since temperature and load conditions vary so much.

 

FWIW, around 2012 or so I had a discussion with a guy at Denso (Denso Aftermarket) who stated he was previously employed at the NUMMI plant in Fremont, CA where the Taco was originally produced.

The NUMMI facility was a joint venture between General Motors and Toyota. That is why so many, and I believe all, of the parts on our HVAC systems are Delphi and not Denso.

Anyway he said the original AC compressor, produced by "Delphi", was then on the aftermarket but now with a Denso badge.

Sure enough, I purchased a "Denso" compressor to discover that its "Denso" sticker of information was rather sloppily attached and revealed there was yet another sticker underlying. I peeled of the sticker to find a "Delphi" sticker underneath with all the same specs. I still have the compressor.

 

Sounds like Delphi built all the original compressors, Denso just remanufactured them after they failed or got scrapped.

Denso makes a good reman product. I use them all the time for starters, alternators, etc