transmission cooler lines '01 4R70W
 

Was doing a motor oil change yesterday when I noticed that the lines leading to the auxiliary tranny cooler were wet at the two retainer clips 12" to 18'' away from the connections. The lines are in pretty good shape everywhere except the two places the clips made contact. The clips were completely rusted and the lines underneath showed galvanic damage. Picking apart the clips and cleaning off the lines exposed a pinhole leak in the driver side line.

Replacement lines are available and inexpensive. I'm not 100% sure how much trouble fishing +36" of rigid cooler line out and in presents.

Because the cooler line damage is in such an accessible location, however, I'm tempted to cut the lines and attempt a repair. I'm considering replacing only the damaged area with a short length of clamped hose or possibly using a compression union.

I am completely open to suggestion on the repair. I would very much appreciate to hear anybody's experience with or opinion on this.

The 5/16" compression fitting would work for a pin hole repair. Do you have a good tubing cutter ? Take your time. Debur the edges. Check for leaks afterwards. Post pics for the before and after repair. Good luck.

Makes sense that a union would work as long as the damage is small, right? Might try using a dremel tool to cut the tubing. Can't think of too many times the damned thing has come in handy otherwise.

I did notice that one Doorman replacement line used a length of 5/16" hose and clamp connection at one end. Makes me believe in the hose and clamp repair as well if I discover more than a pinhole leak.

Thanks for the reply and advice.

https://cimg7.ibsrv.net/gimg/www.for...a860b1f256.jpg
https://cimg6.ibsrv.net/gimg/www.for...f98a2beb8c.jpg

I'm gonna need to look alot closer at the whole line. Good thing that radiator mount rust is out of sight...

Check your transmission cooler while you are looking at the lines. Mine was broken and I had no idea.

https://www.ford-trucks.com/forums/1...on-cooler.html

Wilco on the cooler inspection. What scares me is what the brake line inspection I will be doing uncovers.

Road salt is a wicked, relentless and unnecessary thing.

Ended up using 3/8" nicopp line to replace the rusted factory line. Pretty cheap at $11 for 60" at AZ.

There was no way I was going to try and push a pre-bent steel (or any steel) line through the limited chase. Not after the experience of ripping out the old line. It was an easy thing to fish the flexible tubing through the chase below the fan shroud. I reused the factory fittings and original steel 90 degree bends at the upper and lower radiator connections. Also did this at the driver side aux cooler connection. I took a chance with the compression fittings holding rather than putting a kink the nicopp line. If I had any proficiency with a tubing bender I would have done this differently.

Wound up having to re-tighten three of the four splices due to leaks. The repair looks like it will hold.