I know there are a few threads already, but the other threads do not address my issue completely. I bought a 1989 Toyota Liteace GXL with a 2CT Diesel engine. The place I bought it through performed a replacement of all the coolant system hoses and the radiator has been flushed and filled with new coolant.
I drove the van home to Idaho from Portland Oregon, and when I was pulling into my driveway the check coolant light came on. The next morning I checked the coolant and the reservoir needed a little top up.
But now every two days or so the light comes on and sure as all hell I need to add a little more coolant to the reservoir. There is no noticeable leaks from all the looking I have done.
I also have just today changed the radiator cap out with a Duralast 7913 (its the 4wheel drive cap replacement through Autozone) Im going to keep an eye on it for the next few days, but if anyone else has some info or experience with this issue I would gladly buy you a beer if your ever in Boise Idaho...