Do these transmission oil cooling lines need replacing?

No, but it does give me an indication of your mechanical knowledge.

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My radiator came with new fittings to connect to the hoses. One of the fittings had a defect that had to be filed smooth to make it have a proper metal to metal seal and stop leaking ATF.

Replace the amount of ATF drained when you’re done. The engine must be running. You’ll need to wait for 20+ minutes before the next dipstick reading after adding fluid to let it settle down the tube.

If the fittings go it will leak ATF. Some people will keep driving with a slipping transmission and ruin the transmission.

Just my opinion.
If this is the original radiator, you are running on borrowed time.
If finances allow: replace radiator, thermostat, upper and lower radiator hoses. Take a close look at heater hoses.
Replace rubber transmission cooling lines, drop transmission pan, replace filter and transmission fluid.


I believe it’s the original tranny. The fluid has been changed a few years ago. The only thing is I am planning on a 600 mile road trip in 2 weeks. Bad timing :(. The lines won’t get here for some time.

Is it possible to replace the radiator and cut away the really bad part of the line? Then run a new piece of rubber transmission line from the radiator to the newly cut metal line and use a clamp of two? It won’t have the little tip to the end of the metal line though as it would be cut

I meant if original radiator.

Sorry. I meant original radiator

You’d be far better off by using copper tubing and compression fittings. Route the line carefully, mount it permanently so that the line doesn’t move near the radiator, use a short length of hose to connect near the transmission so that the transmission CAN move slightly on its mounts, make sure it doesn’t leak, then forget it. That’s a permanent fix.

Never use compression fittings in a high pressure system.

Either use a flare fitting, or in your case, a hose barb fitting.

If transmission fluid starts leaking from the radiator, it means the radiator requires replacement. and if you want, the hoses from the radiator to the transmission.


Couldn’t agree more.

Fortunately, the transmission cooler lines are not high pressure.

200 PSI?


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Make sure the new transmission screen is OEM equivalent with very fine mesh. What Oreilly’s sold me was much more coarse than the original. Or just clean it with brake parts cleaner.

It will if you partially flare the end with a regular double flare brake line flaring tool using the first step of the double flare process. Start the double flare step with a shorter portion than if you were doing the full double flare. It will be easier and turn out better.

Aluminum transmission coolers?