Riley,
Since we don't have a definitive answer, the best minds (Robbie, Christo, C-Dan, IdahoDoug, et. al) have recommended frequent changes with a quality coolant. My preference is Toyota Red changed at 12 month intervals.
-B-
>> ... did you flush the block by removing its drain? <<
Of course. :D
I caught a large portion of the fluid from the block in a big bucket. It looked very good with no flakes or grey stuff. I plan to flush/fill every year or approximately 15k miles.
>> ... just trying to make you...
Cooling Sytem Data Point Follows:
First known flush and fill w/Prestone green........8/2/01...........97k miles
Flush and fill w/Toyo red.....................................10/20/02........15k
Flush and fill w/Toyo red.....................................1/10/04..........17k (Now w/130k...
Jody,
Use a good quality anti-freeze. Prestone green or Toyota Red or other "name" brands. Avoid the extended life variants. Frequent flushes appear to be more important than red vs green.
-B-
Kenton,
Your friend would be well advised to do a good heater core and block flush in the near future. The FZJ80 cooling system is one of the areas where good maintenance pays off in the long run. An annual flush and fill is strongly recommended even though that is more than the factory...
Wayne,
I recommend flushing with tap water. Flush the block and open the heater valve to flush the heater core. Remember that you also have a rear heater so it takes time to flush both cores. Flushing the engine block is important; there is a brass plug accessible through the left front wheel...