Well I cant about all environmental conditions, in the salt belt... Condensers only last about 15 years max.. The aluminum starts to oxidize and deteriorate the fins start to rot out etc..
So mostly the condenser, dryer along with the pumps need replaced.
The dye injection will pinpoints the leaks. With the age of these rigs. Its not common for these components to need replaced. Basic wear and tear.
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7 3rd gens listed in the build thread (2 are parts mobiles)
Build Thread:
https://www.toyota-4runner.org/3rd-g...os-builds.html
Brillo's Bucket Fluid Ex changer:
https://www.toyota-4runner.org/3rd-g...ml#post3358086
Sparks Plugs Wire and Coil Information:
https://www.toyota-4runner.org/3rd-g...on-5vz-fe.html