Cooler Lines

[mnBison]

I've currently got my 2015 Yukon XL (106k miles) in the shop to have the AC repaired...a different story... and the shop gave me the usual run down of issues that need to be addressed.  2 items that they mentioned where the transmission cooler lines and engine oil cooler lines were both leaking.  They are not the first shop to tell me that these are both leaking (and make it sound like there is an immediate need for replacement).  I recently replaced transmission fluid on this vehicle and inspected the lines myself and I agree that the oil cooler lines have residue around the couplers, I think leaking is a strong word for my what I am seeing.  I don't agree that the transmission lines have any issues.

 

My questions for everyone, is it really that uncommon to have some residue around couplers for these lines?  When I haven't seen any evidence of oil/fluid on my garage floor and neither fluid is unexpectedly dropping, any reason you'd rush out to replace these?  I certainly feel like a little residue on these lines is the reality of running a complex machine and until it is noticeably losing fluid, replacing them would be a waste of money.

 

Thank you for any input!

[Tahoe02]

If there are no spots on the floor and the level is not dropping considerably on the dip stick then I would not worry about it. You could also clean them with some brake clean on a rag and just keep an eye on them. When you do decide to replace them just get the part # from your Dealer and look on Ebay. Dealers sell on there all the time at a discounted price with no tax and sometimes free shipping.

[seamus2154]

I agree. Sweating and weeping are not leaking. I routinely check everything at every oil change. I use brake clean when ever I have a leak and then check again soon to see if it is weeping/sweating or leaking. On my '17 nothing is weeping. Just make sure you confident they are snapped in and secured correctly. There were issues mainly with the '14 pickups where they were not snapped in correctly. My Zo6 rear diff has a similar cooling line that has to be disconnected to drain. It snaps in the same way. I didn't hear it click when reinstalling it. Pulled on it and it was in....nope gave it a yank and it popped out. Did it a second time and clearly it went in and clicked.

[Sierra Dan]

Unrelated to a Yukon, but i had some weeping in the connections of my coooer lines and

dealer replaced under warranty.

Just a small sweat weep. No heavy dripping.

[Riklimoguy]

Had my Trans lines leaking for about 100k miles.. 

Lots of 15 models have same problem.