NCES300

I own a 2002 ES300 and my overflow hose has im not sure another way to describe it as when a battery gets corrosion on it but like that around the hose where it connects to my cap it also had it on top of my coolant reservoir and the other day when I was looking it was built up and my cap was off I ended up cleaning the top of the reservoir and the cap so it would fit on there good is this just built up coolant fluid thats gotten out since the cap had came off or should I replace the overflow hose or could I just cut the hose a little on the end if its due to a crack or split in it?

LeX2K

What you're seeing is dried up coolant. Try cutting 1/2" off the hose it might fix the leak or replace the hose it's not expensive
https://lexus.oempartsonline.com/oem...cap-1640520060

Anytime I see crustys I suspect the coolant needs to be replaced. Also check for radiator leaks, and if the coolant cap is original replace it with 16401-62090. I think someone here had the coolant neck itself leak where the nipple (what the hose is on) fits into the aluminum housing.