New radiator and flush

[MaximaGuy]

I am going to install a new radiator and it is recommended to flush the entire old coolant out before installing the new one.

I like the Bob's (site owner) method to run a water hose thro the radiator but then I live in an area where the water is hard (the water district said it had 225 PPM/Galon). Could I just flush it with tap water and towards the end use distilled water? Now that way I will have distilled water in the block towards the end and fill the radiator with 100% coolant and over time they mix.

Any suggestions.

 

[porcupine73]

I had a similar issue as I have hard well water with sulfur and iron, so I filled a 15 gallon tupperware container with about 11 gallons of distilled water (cost about $9), and hooked up a submersible pump from harbor freight to the lower radiator hose and back flushed the thing before putting in new coolant. It wasn't the cheapest way but it didn't cost that much and i know it's all good water in there; could also use RO water if you have it.

 

[Laminar Lou]

Awesome idea with the submersible pump! I have one to drain my spa, never thought about using that to flush the system. I have the same problem with hard water, so I was going to use distilled water too. But I was going to have to do the drain and replace method and it would have taken all weekend to get 3 or 4 drain and replace cycles through it.