flushing coolant

[cams-76]

i want to change my coolant and haven't really ever "flushed" a coolant system. Does this mean drain it and run water through the radiator with a hose? And what coolant is recommended? The previous owner had a bottle of additive stuff he put in every time he changed the coolant. thanks

[daveyburt]

there is an International Harvester coolant that is red and concentrated. It does not require additive and is supposedly good for 300K.

as far as the flush, buy lots of distilled water. i used about 28 or so gallons to flush mine...cleaned out a grocery store and had to go to another.

when you drain the radistor thru the drain peckock you will drain 4 gallons. the total capacity of the system is 8 gallons.

drain 4 and add 4 gallons of tap water.
run engine until heat blows hot.
drain another 4 and add 4 gals of tap water
run to get heat
...and repeat.

keep doing this until you get clear water from the drain peckock....takes about 8 times or so but, that could vary depending on the cooant concentration you currently have.

after you get clear water from the peckock start the process over using the distilled gallons.
drain 4, add 4 distilled
run till hot
-repeat

keep doing this until you've added all 28 gallons. at this point you should be pretty close to all distilled in the system.

drain 4 and add the 4 gallons of red concentrate.
this give you the 50/50 mix and you should be good to go.

sometimes air may get trapped in the upper heater hoses and you may have problems getting heat. you're up to your own devices to rid the system of air.
normally removing the hose that's the highest in the system will burp it.

keep a gollon of 50/50 mix for top offs.

it takes a while but is simple....thank NCHornet for the recipe