Looks like the last thing I need to do to the newly acquired truck is replace the trans cooling lines. Slow leaks are evident as fluid hanging on the low spots of the lines just behind the aux cooler.

Noticed this while replacing the idler arm (and the rest of the steering and suspension) last weekend. My mechanic that does stuff for which I need a hoist or highly specialized tools confirmed that replacement is mandatory, as soon as possible. I had him look at the issue while he was inspecting my front end rebuild. He said I could do it myself but his shop was too busy for me to stand around bending his ear for pointers at the time.

Bought the stuff I think I need from RA. Fingers crossed that I got it all.

I've searched YouTube and the manuals I have for proper procedure. Searched this site fairly well too. I can't seem to locate even a rough step-by-step.

I don't know jack about Auto transmissions. I don't want to go charging in blind and screw something up.

Can anybody tell me where to start or provide any do's or don'ts? What else should be done while I'm under there? (still reeling from the front end rebuild $$$)

Any advice will be appreciated. 4R70W with aux cooler.

Thanks!

 

Are the tubes preformed? If so seems like it would be just unscrewing the connections and re-installing. I've never done it but I've added coolers to transmissions before. You shouldn't lose much fluid, not enough to worry about.

 

Yeah...they're all pre-bent with the flex sections in the middles.

I was wondering about the fluid, among other things. Didn't know if I had to drain it first. I did find out that those things like lots of expensive liquid.

 

You don't need to drain the trans you might lose a quart changing the lines. It will not drain the trans.