I'm going to replace my coolant for the first time (at 25k miles, ~3yrs). Should I just drain and refill or should I do a flush with water as well (not a chemical power flush or anything). Looking at the Helms and Haynes manual, flushing seems to involve a lot more work ie: taking out the thermostat and hoses and such. THe Helms doesn't even cover flushing.

Also should I use distilled water to mix coolant or will tap water suffice? And should the heater temp be on max and blowing air the whole time I do this?

Thanks for any help!

 

You want to flush it. This means the car should be running while you poor in the 50/50 mixture of water and coolant and drain it out at the same time. I just use tap water for the mixture. It should suffice. I can't really think of a reason why you would have to use distilled water. HTH

 

When I changed my coolant all I did was pull the drain plug, lower radiator, and the coolant drain bolt on the bolt, it drained a considerable amount so I doubt there was any significant amount left in the system.

Distilled water lacks the minerals and sediment contained in your tap water which eventually can cause clogs and what not. If you're justing using it to flush however, there shouldn't be a problem.

 

I would say that for a new car (3 yr/25k), you simply drain the old stuff out and replace it with new HONDA radiator fluid, and DISTILLED water. You want to keep all of the minerals and other stuff in tap water out of your system. If it were an older car, AND there are overheating concerns, I would flush it.
And you should put the heater on hot setting to let the coolant drain out of the heater block, NO fan running. Car should be OFF.
Have fun...and be safe !