Coolant leaking from transmission cooler line

[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

There may be special coverage on this. Check with your dealer before you spend money on your own

 

[swathdiver]

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.

Just put a wrench on it and give it a little push. If that doesn't fix it, replace the o-ring or fitting. If that doesn't do it, well then it's time for a new ACDelco radiator. Don't mess with aftermarket unless that Japanese one, Mishimoto or something.

PN# 21742 but double check with @915_Tahoe; give Rene the last 8 of your VIN and he can look it up for you.

 

[muncie21]

Just put a wrench on it and give it a little push. If that doesn't fix it, replace the o-ring or fitting. If that doesn't do it, well then it's time for a new ACDelco radiator. Don't mess with aftermarket unless that Japanese one, Mishimoto or something.

PN# 21742 but double check with @915_Tahoe; give Rene the last 8 of your VIN and he can look it up for you.

Great suggestions. The last 8 of my VIN are: ER158651 It's a 2014 AWD Yukon XL Denali with 6.2 motor

 

[oldchev]

My 2004 Yukon has had coolant leaks at these points twice. I believe the o ring responsible is inside the tank. After looking at the tank securement I felt the chances of further leaks elsewhere where too great and considering the work doing r and r of radiator was enough to just warrant a new radiator. I did that and problem solved for 4 years until it did it again. Seems like problem area. -N

 

[OR VietVet]

I think it is important to note that the lines, on either side, should be secured with a strap or clamp of some sort along the way in at least one place if not at least 2 places so that the weight of the lines is not just dangling where they are routed. Sometimes when work is done and these straps/clamps are removed they don't get put back in place.

 

[915_Tahoe]

Gm#15226661 $6.38 each, takes 2
Trans connectors

O-rings not serviced, part of the connectors.

 

[muncie21]

After multiple washing of the area and inspections, it now looks like the leak/seep is coming from where the plastic tanks are attached to the radiator.

I ordered a Spectra Premium CU2370 radiator (w/oil & trans cooler) from Amazon (~$120/shipped) as I needed the radiator quickly didn't want it to arrive after Christmas. In addition to the radiator, I ordered upper/lower radiator hoses and a new thermostat, since I have easy access to those.

I'm going to install it during the holidays and then check again for leaks. Hoping this fixes the issue and I'm not replacing more hoses afterward.

 

[OR VietVet]

There are threads here about getting the wrong radiator, even though it fits fine, where the coolant return spout to the coolant reservoir tank has a small restriction from the factory and if put in a radiator without that your will have problems with low engine temp, if I remember right.