by chriscarter » Wed Oct 12, 2011 4:45 am
To properly flush the entire cooling system, you will also have to flush the heater core. To do this, disconnect the heater hoses at the engine and run your garden hose (low pressure - NO nozzle) into these hoses in the direction of the firewall. Be sure your heater controls inside the car are set to full HOT. This will ensure that the heater control valve is fully open. Of course, this is all done with the engine OFF. Flush the radiator, heater core and engine in both directions (alternate hoses and top/bottom of radiator and engine). Be aware that there is a drain on the front of the engine block also.
That's about it. I prefer the non-diluted type of antifreeze/coolant, not the "ready to use" 50/50 mix. You're paying a lot more for the "ready to use". Just be sure that all of the water you used for flushing has drained out of the system before refilling with coolant. If not, you won't be able to refill with enough antifreeze/coolant concentration. Read your owner's manual or service manual for total cooling system capacity.
VERY important - This may be obvious without saying, but I'll say it anyway.......flush your cooling system when the engine is fully COLD. Let it sit at least 2 hours after driving before starting to flush the system.
PS - Almost forgot...after you have fully refilled the system (do it slowly and wait for the water to get everywhere in the system), run the engine at idle (heater control still on full HOT) until the thermostat opens, then top off the system. You can tell this by feeling the hose closest to the t-stat housing. When it gets hot, the t-stat has opened. You should be refilling at the radiator itself, not the white plastic overflow tank. Observe all precautions when dealing with a hot, pressurized cooling system. DO NOT remove the radiator cap on a hot engine!!
