I have a leak issue with one of my vehicles, a 2000 Toyota Tundra, but I would like to ask in a more general sense so that the thread may be of more use to others.
From what I understand, leaks at connection points are often (usually?) caused by failing O-Rings, however corrosion of the fitting itself can cause leaks past the O-Ring as well. My question is, are defects in the line at the connection point usually visually apparent? That is, if you disassemble a connection and remove the existing O-Ring, can you easily tell whether the line is in good condition or needs to be replaced?
For context, on my truck I had very apparent leaks two years ago on the high side at the connections to the condenser as well as the receiver/dryer. The local Toyota dealership replaced the O-Rings and evaporator as the evaporator was starting to loose some fins at the bottom due to corrosion. The tech's notes state that after the replacement they verified that there were no leaks (by whatever standard that may be).
Fast forward to this Spring, two years later, I noticed a drip of bright green oil forming on one of the condenser connections while changing the timing belt. It's possible I could have bumped the line with the radiator while pulling it out, not sure if that could have contributed. Unfortunately I didn't notice whether it was leaking before I started the job.
I brought it back to the dealer and told them where it was leaking, and their diagnosis consisted of spraying soapy water on the connections and confirming that it was leaking where I said it was and also at the connections to the receiver/dryer. They concluded that since the O-Rings had already been replaced, it must be the lines and quoted $1600 to replace those.
Yesterday I brought the truck to a smaller shop that specializes in AC work. They recommended thoroughly cleaning the connections and replacing the o-rings again, and that they wouldn't be able to tell whether the lines were good before doing that. When I picked it up, the mechanic had already left for the weekend and so I wasn't able to find out what kind of condition the lines were in and whether they expected the o-ring replacement to work. After getting the truck home, I found that they had somehow gotten oil/dye all over the underside of the hood, on the air box, and down the front bumper. There was also oil on the receiver/dryer which makes it hard for me to tell if it's still leaking. I sprayed a solution of simple green and water on the area with the compressor running and didn't notice any bubbles, but I'm not sure if simple green is 'bubbly' enough.
Being in the northeast the truck is certainly no stranger to corrosion (Toyota replaced the frame in 2010), but the lines don't look that corroded to me on the outside (of course, it's what's on the inside that counts
). Photos attached that were taken this morning after doing my best to clean up all the oil last night.I guess my main concern is that, if it's very hard to tell whether or not the lines are bad, how can I be sure that replacing the lines will fix the leaks?
