When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I have a frustrating problem with my GX. It's leaking a little transmission fluid from where the cooler line connects to the radiator. It does not leak when the car is cold or when its just parked. But after driving it around a bit and letting pressure build in the radiator I noticed fluid leading from the passenger side of the car. I had this problem a few months ago and had the dealer replace the radiator. After a few months I noticed the leak and took it back to the dealership and they said it was a faulty radiator and replaced it with another new one. It was not leaking for the first couple of weeks but after I took it on a 400+ mile trip I noticed it was leaking again from the same spot. This is the second radiator I've replaced in 6 months and I'm starting to think it's not a problem with the radiator. It is leaking from where the lower transmission cooler line connects to the radiator. Its the one right above the radiator hose on the passenger side of the car.
The car has over 123k miles and the fluid has never been flushed. I'm planning on doing this tomorrow. I've read in some GS forums that the problem could be old transmission fluid that is getting too hot and causing the leak. The valve where the transmission cooler line plugs in looks like there is a socket that screws into the radiator. Is it possible to loosen it up and put Teflon tape around it to seal it better?
Does anyone have any ideas or input?
If it's leaking at the connector (and not from the hose crimp) then it's probably an installer mistake. Either they're not doing it right, or perhaps they cross-threaded it in the past. The hose assembly might need replacing now.
Explain this is the third time, and ask for their senior technician to look at it.
If it's leaking at the connector (and not from the hose crimp) then it's probably an installer mistake. Either they're not doing it right, or perhaps they cross-threaded it in the past. The hose assembly might need replacing now.
Explain this is the third time, and ask for their senior technician to look at it.
Chip H.
The last time I got the radiator replaced by them it took me over a week of constantly calling them, Bi*ching, yelling, making threats to contact the BBB, etc before they decided to "do me a favor" and replace the radiator again. It took me almost 2 weeks to get my car back. I don't have the patience or the time to deal with them again and I'd just rather do this myself.
Please conform the engine oil has no coolant in it and the trans fluid has no water in it. The oil to water heat exchanger can crack and cause both these to happen but yours sounds like an external leak.
Have you tried tightening the fitting?
Stock, most OEM installs will run a steel line with a compression fitting. Unscrew the fitting and look real close at the lines end for cracks. A tiny split in the flare where it mates to the heat exchanger can cause your leak.
If it were mine to deal with I would approach with a replacement piece of tubing having a double flare end and a brass union butt connector. You'll need a pipe cutter and cut the split off. Reuse the nut on new pipe, cut new pipe to proper length and install on heat exchanger. Mate the pipes with the onion.
Please conform the engine oil has no coolant in it and the trans fluid has no water in it. The oil to water heat exchanger can crack and cause both these to happen but yours sounds like an external leak.
Have you tried tightening the fitting?
Stock, most OEM installs will run a steel line with a compression fitting. Unscrew the fitting and look real close at the lines end for cracks. A tiny split in the flare where it mates to the heat exchanger can cause your leak.
If it were mine to deal with I would approach with a replacement piece of tubing having a double flare end and a brass union butt connector. You'll need a pipe cutter and cut the split off. Reuse the nut on new pipe, cut new pipe to proper length and install on heat exchanger. Mate the pipes with the onion.
Let us know what your inspection finds....
I'll remove the fitting tomorrow and take a look at it. Hopefully its just loose fitting. Is it OK to use Teflon tape to seal up the threads?
Last night I took out the two hose fittings, wrapped them both up with teflon tape and screwed them back in. Then ran the car for about a half hour. I made sure to clean up everything with brake cleaner so that I could see if it happened again. I did not notice any leaks. Today I flushed the trans fluid twice, let it run for a half hour then drove it for a bit. No leaks. I'm still not sold that this will be end of the leaks. I think the incompetent techs who installed the radiators were either over tightening the fittings or cross threaded them. The fittings seemed a little soft and easy to damage.
11-06-17, 07:19 AM
Leaking transmission fluid from radiator cooler
