Easiest way to deal with leaking transmissions cooler line(s)

[avid]

One or both of my transmission cooler lines are leaking. Is there a way to fix this temporarily until I have time to deal with my rust-mummified Cat-to-Y-pipe connection, which apparently needs removed to access the cooler line connections on the transmission?

 

[franklin2]

I have been repairing them. It really ends up being a permanent repair IF, the ends of the lines are not rusted. I use NI-COP line, you can get it on Amazon or the local store in rolls. Some of my cars have 5/16 line, some have 3/8. The 2002 F150 I am working on now has both 5/16 and 3/8 all in one line, thanks Ford.

I then cut the line and use brass compression fittings like the picture below. You can get these at Lowe's or the hardware store, but I found the auto parts stores sell these also a little bit cheaper.

Judge the condition of the line, and find a flat place to cut it that is not rusted up. Use a compression coupler, then you can use the new NI-COP line, and run it up front till you get to another spot where you can use another coupler. I like to use NI-COP because it doesn't rust, and it's so easy to bend by hand.

If the rest of the line is in good shape, this ends up being a permanent repair.

 

[avid]

I have been repairing them. It really ends up being a permanent repair IF, the ends of the lines are not rusted. I use NI-COP line, you can get it on Amazon or the local store in rolls. Some of my cars have 5/16 line, some have 3/8. The 2002 F150 I am working on now has both 5/16 and 3/8 all in one line, thanks Ford.

I then cut the line and use brass compression fittings like the picture below. You can get these at Lowe's or the hardware store, but I found the auto parts stores sell these also a little bit cheaper.

Judge the condition of the line, and find a flat place to cut it that is not rusted up. Use a compression coupler, then you can use the new NI-COP line, and run it up front till you get to another spot where you can use another coupler. I like to use NI-COP because it doesn't rust, and it's so easy to bend by hand.

If the rest of the line is in good shape, this ends up being a permanent repair.

Thanks for the reply. What do you use to cut the line? Just like a small hacksaw? Do you have to de-burr? So with those compression couplers you don't need to flare the line?

Thanks again for the info.

 

[lil_Blue_Ford]

Thanks for the reply. What do you use to cut the line? Just like a small hacksaw? Do you have to de-burr? So with those compression couplers you don't need to flare the line?

Thanks again for the info.

Best way is to cut with a small tubing cutter and yes to de-burring. No flare for compression couplers, just don’t use them on brake lines. You could also use a section of rubber transmission lines either and hose clamps for a temporary repair.

Personally, I replace the whole set of lines either when they go or when I have things apart to get to them. Ni-copper lines or usually for me, aluminum. Might try stainless now that I have a good flare tool.

 

[franklin2]

Best to go buy one of these. You will use this for many other things and is something good to have laying in the tool box. Just make sure you get a small one, sometimes you do not have much room under the truck beside the transmission to spin it around to cut the line. It will leave a nice clean cut that is easy for the coupler to slide on.

These compression couplers have a ring inside, looks just like a wedding band. The band just slips over the outside of the line. Then the nut presses the band up into the main fitting when you tighten it, and the main fitting has a taper that accepts the band. As you are tightening the nut, the band gets squeezed tight around the line, making a good mechanical seal. You can take the fitting apart later on if you need to, but the band will never come off again and has to be cut off for major changes later on.

Amazon.com