Coolant leaking from transmission cooler line

[muncie21]

I have a 2014 Yukon XL Denali with the 6.2 motor. I recently noticed that there's minor coolant leak/seep from the transmission cooler line, where it connects to the radiator side tank on the driver's side of the vehicle.

Thinking of tightening the fitting where it connects to the radiator, however I'm a bit concerned about cracking the plastic tank when I do this. Alternatively, does anyone know if there's an o-ring in this connection? If so, I may try to just replace the o-ring before I spend $$ on a new radiator and transmission line.

 

[wjburken]

I have a 2014 Yukon XL Denali with the 6.2 motor. I recently noticed that there's minor coolant leak/seep from the transmission cooler line, where it connects to the radiator side tank on the driver's side of the vehicle.

Thinking of tightening the fitting where it connects to the radiator, however I'm a bit concerned about cracking the plastic tank when I do this. Alternatively, does anyone know if there's an o-ring in this connection? If so, I may try to just replace the o-ring before I spend $$ on a new radiator and transmission line.

If you are seeing coolant, replacing the o-ring or tightening the connection will not help. You most likely have a crack in the radiator around the transmission line.

 

[OR VietVet]

If the line unthreads from the radiator ok you should not need a line. If you are leaking coolant from the line itself then you have coolant in your trans fluid. The only thing that should leak from the line is trans fluid. If you are talking about the fitting in the radiator, do not try to tighten. You will likely crack the radiator. If the fitting is leaking at the radiator then you need a radiator. Pics?

 

[muncie21]

The leak is definitely coolant and coming from where the fitting screws into the radiator. Found out that the auto parts place around the corner carries just the fitting. May try to replace it with a new one and o-ring before ordering a new radiator.

 

[wjburken]

The leak is definitely coolant and coming from where the fitting screws into the radiator. Found out that the auto parts place around the corner carries just the fitting. May try to replace it with a new one and o-ring before ordering a new radiator.

View attachment 236471

If you take that fitting out, you better hope only transmission fluid comes out. If coolant comes out, you need a new radiator and a transmission flush.

 

[muncie21]

If you take that fitting out, you better hope only transmission fluid comes out. If coolant comes out, you need a new radiator and a transmission flush.

Good point. Hmmm, sounds like a new radiator needs to be added to my Santa list

 

[OR VietVet]

I have a similar problem now except it feels like a hard transmission shift. It mostly happens when cold and rolling down the street out of my driveway. As I make a slight right turn and am about to give it some gas it hard clucks into another gear.

The leak is definitely coolant and coming from where the fitting screws into the radiator. Found out that the auto parts place around the corner carries just the fitting. May try to replace it with a new one and o-ring before ordering a new radiator.

View attachment 236471

Like Wade said, careful when you attempt to tighten. If is loose that means at one time you or a tech may have loosened the LINE and did not put a wrench on the fitting to hold it in place. Shit happens.

 

[kbuskill]

I have a 2014 Yukon XL Denali with the 6.2 motor. I recently noticed that there's minor coolant leak/seep from the transmission cooler line, where it connects to the radiator side tank on the driver's side of the vehicle.

Thinking of tightening the fitting where it connects to the radiator, however I'm a bit concerned about cracking the plastic tank when I do this. Alternatively, does anyone know if there's an o-ring in this connection? If so, I may try to just replace the o-ring before I spend $$ on a new radiator and transmission line.

FYI...

if the lines you are looking at go to the drivers side of the radiator then those are for the engine oil cooler NOT the transmission.

Transmission lines go into the passenger side of the radiator.

 

[wjburken]

FYI...

if the lines you are looking at go to the drivers side of the radiator then those are for the engine oil cooler NOT the transmission.

Transmission lines go into the passenger side of the radiator.

I completely missed the “driver’s side” statement.

 

[PoorMansEscalade]

You most likely need a radiator, gm has a bulletin about this. They are blaming the thermostat for the problem. I believe there is