Rerouting transmission cooler lines

COLLEEN GORDON

MEMBER
2008 FORD FUSION
6 CYL
AWD
AUTOMATIC
165,000 MILES

Hello there,
Recently I noticed I had a small leak in one of my transmission cooler lines right where the clamp that holds it in place and is attached to car. I tried to patch the pin size hole until I could replace the coolant lines. Unfortunately even with gentle touching the lines were so rusted that another bigger hole appeared where the other plastic clamp was from being rusted right through. My mechanic decided the best option was to reroute the transmission fluid so they do not run through any cooler lines and mount and install an external cooler so that the can be cooled that way. The reason being the clamps that attach lines to radiator are so rusted and the difficulty of removing them and more damage that may happen to more parts and the cost. He said the risk is too high.
My concern is that for the next week my transmission fluid has no way to be cooled until external cooler can be installed. Mechanic says car is safe to drive for small trips. Unfortunately I need to drive to pick up my children about an hours drive away. Its back roads and no speeds over fifty mph but a few hills as I live in Vermont. Plus the weather has been very hot. Roughly eighty plus degree lately. I do not want to be stuck on a back road with three kids and a broken transmission that will cost me more than the car is worth. Is this trip safe to take once? Car will sit for a day or so between arrival and departure. I just need to get there and back but not on same day. Will this be safe?
Thanks so much.
Worried mom

3 Replies

CARADIODOC

MECHANIC
33,916 POSTS

I would get a low-cost rental car for the trip. The engineers at Ford figured out they could save a lot of money years ago by leaving off four important grease fittings, at a nickel a piece, then letting the owners handle the crashes that resulted from the prematurely worn and broken steering parts. Do you think they would spend money to put a transmission cooler on your car if it was not needed? The problem is you may not notice a problem on the trip. An overheated transmission, especially in hot weather, is like drinking sugar-laced soda and eating candy all day long every day for years. You will not get cavities right away, but you will get more than most people. Overheated transmission fluid destroys the additives in it that help it function properly. You are more likely to suffer decreased transmission life due to melted rubber seals and reduced lubricating properties of the fluid.

I can understand adding an aftermarket transmission cooler, but until that is installed, the cost of renting a car is real low compared to the cost of rebuilding the transmission. Be aware too under many driving conditions, more heat is generated in the transmission when driving at slow speeds in stop-and-go traffic. The least heat is generated when driving in the highest gear, and when the torque converter has locked up for better fuel mileage. That typically occurs above thirty five to forty mph.