Radiator Coolant Flush!

[gotmyeclipse]

Hi there, i wanted to flush my radiator from any dirt or rust thats in there, so my question is: do i drain the coolant then use a garden hose to flush out whatever is inside? or do i just drain and fill?

 

[clipto]

Just shove the garden hose in there awd let it drain out the bottom till it looks clean.

 

[NHerron]

I don't like using a hose for this, I'm picky.

But when the price of distilled water by the gallon is cheap enough why not, so here's what I do, every year on every vehicle, and does the job very well.

With the engine cold, drain the radiator via the petcock (dispose of coolant properly. At least keep it away from animals) our radiators have a nice little nipple below the petcock for a hose to slip onto, you could use the coolant overflow tube so you don't make a huge mess.

Dump in a thing of Prestone super radiator cleaner (this can be found at any Wal-Mart or auto store) in the radiator, and fill radiator the rest of the way with DISTILLED water (approx .8/Gal). Now drive around a couple days like that.

After a few driving cycles, let the engine cool and drain the radiator. Close the drain. Fill it back up with another gallon of distilled water (approx .85/Gal). Drive it around and repeat this step two more times.

Now that the engine is full of basically just pure distilled water, drain the radiator for the second to last time. Buy a gallon of straight antifreeze (not premixed) and fill the radiator. You'll notice you have a bit of coolant left over. SO, run the engine at least one heat cycle to mix things up. Cool it and drain it until it equals what's left in your coolant bottle. Close the drain and fill with the rest of coolant. DONE!

Optional, you can add a thing of Redline Water Wetter, it's some good stuff. Now would be the time to change the radiator cap, thermostat, and check the coolant overflow system for proper operation. Basically pull the hose off the thermostat housing, take the cap off overflow. Try to blow through the hose to make sure of no obstructions. Now plug one end of the hose, suck, and see if it holds pressure.

OEM cap is 13psi
OEM thermostat is 190*F
Total coolant system (radiator, block, heater core) holds 1.9Gal and radiator by itself holds approx. 0.85Gal

I didn't mean to make a damn article I just got carried away I suppose

 

[Slahm]

If you are REALLY trying to clean it out, nothing beats having it hot-tanked by a rad shop. I have seen this cost anywhere from $25-200 bucks, depending on how friendly/busy they are, etc... Whether you are in a rush.

If you can get it done at the lower end of this, it may be even cheaper than buying radiator cleaners, but you would have to really luck out.

Works great though, and will flow like brand new!