Hi,
Both my transmission cooling lines just started to leak at the point where they snap into the holder. Can I just cut the line behind the leaks or do I need to get new lines? I noticed the line have a bump in them that the hose slides over. Also what type of hose do I need?

Thanks

 

Yes, you can cut the lines and use "rubber" hose to splice it, no, I don't know the size

These lines don't "technically" have pressure since one end is open where fluid flows back into the transmission pan from the cooler
But there IS high flow from the pump in transmission to cooler, so there is back pressure
Google: Transmission Oil Cooler Hose

Most use double clamps
But make sure the metal tube is solid, if part of it was deteriorating AND Leaking, then other parts may be as well, clamps only work if the metal tube is solid to squeeze the hose against

Yes, a "bump" in a tube helps hold hose and clamp from sliding off, which is why the double clamps, friction of tight fitting rubber hose against even smooth metal is high

 

On your 2004 V6~4.0L~SOHC, the TransCooler ATF Hoses running forward under the radiator should be 10mm or 3/8" ID.
Standard\stock 100psiMinRated HydraulicHose with DoubledUp WormClamps from a local PartsHouse,
worked for me.