When I had the LS400...

This is the only 10mm hose that I could find that's compatible with ATF. Yes, the color is odd, but it's not readily seen when you open the hood.

https://www.clublexus.com/forums/ls-...l#post11472247



https://www.mcmaster.com/

 

10mm hose ID = .393"
3/8" hose ID = .375"

The difference may seem negligible, but it's the flare (hump) on the end of the hard line that creates an issue. 3/8" hose will be too tight to go over the flare.
If your goal is to find exact 10mm ID hose, then Paulos solution is the best and likely the only option.

Most online sellers might offer 10mm hose, but if you notice it's also labeled as 3/8" hose. (10mm / 3/8") They don't care, they just want to sell the product.

The most realistic solution is to buy 3/8" hose from a local auto parts store. Use a 25/64" drill to hog out the ID of the end of the hose for a better fit.
25/64 = .391"

 

This is nice. Made in Germany hose. Rather have this than chinese knockoffs. BOught one. Which clamps did u use? OEM? any fitting issues with clamps?