I just drained, flushed and refilled the radiator. My question is how much 50/50 mixture should be going back in? The manual says 10.4 quart system capacity or roughly 2.5 gallons. I realize there is probably some that did not drain out, but I am only getting about 1.5 gallons total to go back in. I have let it idle for 10 minutes twice and topped it off and run the heater thinking this would recirc some of it. Does this sound right? Is this like the oiling system that has a 7 quart capacity but you only change 4 quarts? Thanks for any thoughts or experiences.

HD

 

5 - 6 qts is normal if you only drop the radiator drain plug

 

all 13b engin have a drain on the right side at the engin mount area. You could drain 70-80% of the coolent out that way. that is a better way to change coolant, but in most case refilling require a lot of time cause air bubbles in the systems.

 

yeah, thanks for telling us that, the manual makes no mention of it

 

The stuff that came out was a dark green color and looked to be in really good shape for 37,000 miles in a rotary from down south. I went back with a 50/50 mixture of yellow prestone (Ethylene Glycol) and distilled water. This was a very easy job. The manual says this should only be performed by a certified Mazda mechanic or something like that. Nonsense. Piece o' cake. I'll be doing this every year instead waiting two years.