Transmission cooler line on F-150

Hi, I have a '91 F-150 with a rusty, leaking tranny coolant line. Access to the transmission fitting is VERY difficult. I attempted to remove the fitting from the outlet port on the tranny, and my line wrench couldn’t get it loose. Then I munged it up with a pair of vise-grips. So now I’m thinking of cutting out the portion of the line that’s rusted, and splicing in a rubber hose with some hose clamps. Of course I’ll route it so it can’t touch the exhaust system. Is this a high pressure line? Do I need special hose or can I use fuel hose? This is an off-road farm vehicle, so I’m not worried about highway safety. Thanks, guys.

Not very high pressure at the cooler line, but you should try to get hose that is designed to hold oil. After a few years, fuel line gets soft and splits when it’s transporting oil or transmission fluid.

You have the right idea, though, cut the steel line, slip the rubber hose in the gap, but unless you have a tool to flare the ends of the cut steel lines, I would suggest using four hose clamps (two per end) on the job to ensure there are no leaks.

Best of luck!

Do yourself a favor, and instead of using rubber hose use a steel or even copper line, and attach it using compression fittings.

Install it, check it carefully for leaks, then forget about it forever. If you use hose you’ll always be checking it for leaks, and probably finding some.

Thanks, gentlemen.