2000 Tundra radiator leak source

Pink is the way to go. Red is standard life and IAT. Pink is the long life stuff and OAT. Pink has a significantly longer lifespan. I believe red is 30k/2yr and pink is up to 120k/6yr. I want to say pink has some additives to it also, and I don't think I've ever seen it in any form except 50/50.

 

Ok - thanks for everything from everyone who chimed in. This is a great group! I changed the rad, the hoses, the t-stat, and gasket. I flushed the rad with distilled water until pretty clear - about 6 gallons of water. I replaced with red concentrate and distilled water. Along the way an embeded nut on the skid plate gave up the ghost (it started to spin - as it dug out the plastic it was originally held by - would like to fix this if there is any advice). I also lost some atf. When I went in the house to look something up, one of the two hoses that go into the bottom of the radiator to cool the atf, dropped down and started to drain. I have replaced the fluid but may have added too much. Again not sure, but this morning I checked the atf dipstick and it was in the hot range with the truck being cool. Keep in mind I don't have much of a level surface to check and don't know if this make it worse (as in even more overfilled than it indicates - the truck sits on an incline with hood higher than tail). But all in all the rad has been replaced by denso and good, red coolant is in the truck after a nice flush.

 

Make sure to have truck running (it's better if it's warmed up) park on level surface, run it through every gear on the shifter, then pull stick and check level while still running.

 

For what's it's worth I saw this on their site:
Service life of up to 15 years/400,000 miles with a complete cooling system flush and fill.