HELP, The Mrs car issue

All right guys and gals, I need your help with this issue on my wife's car, 2010 Buick LaCrosse cxl with a 3.0, transmission cooling lines are leaking they are going to get fixed tomorrow, the other issue is the radiator fluid in the reservoir tank keeps getting low, there is no white smoke at startup or idle there is no milky oil in the oil dipstick and there is no sign of leaks on the ground, and it's not overheating at all also the wife's best friend's husband is a mechanic put a pressure test on it, and it held pressure , any other ideas???

 

No smaller leaks/cracks in the radiator anywhere?

 

Brand new radiator was installed a year ago

 

I vital the car for a solid hour, no leaks anywhere on the ground

 

Have you checked around the hoses and water pump area for signs of a leak? My stepdaughters car is having the same symptoms right now, but hers is a small leak where the transmission cooling lines connect to the radiator, maybe another place to check...The fitting is where hers leaks (very minimal) the reservoir will go down to the low level about once a month.

 

What's the transmission fluid look like? Any chance coolant is mixing with transmission fluid?

 

May have found the culprit, water pump, semi oily residue on ground, as the engine faces sideways, but for sure transmission cooling lines are getting changed

 

Hopefully it's a quick fix and solves the problem.

 

Thanks for response

 

No problem. Since we're on the topic....I really need to swap out the radiator on my stepdaughter's car this weekend (since I'm having shoulder surgery next Friday and will be down and out for a bit). In the picture above - have you ever seen a transmission cooler line that connects like this? Will it be reusable? In the pictures I've seen the new radiators appear to just have a threaded hole where this fitting would screw into, but I'm not sure if they can be reused or if I need to track down a replacement before taking anything apart. Car is an older beater with low mileage. 1998 Mercury Tracer if that helps any.

 

Yes transmission cooling lines go into radiator on the right side and the the one line leaks right on top of the lower radiator hose

 

If mine is currently leaking at that fitting (where the upper trans line connects to the radiator) is that just a radiator swap or will I need to replace that fitting also? The new radiator doesn't appear to come with one. Unless I'm wrong, it looks like the trans line goes into an insert and the insert is threaded into the radiator. I've changed radiators before, but haven't seen the trans line connected like that.

 

Thanks to all who replied