apex2k

I wanted to flush the coolant system on my 1992 Accord and all went well except for getting the plug out of the block (tight space and 268,000 miles working against me). The dealer had done this for me in the past but as tight as the plug was I have to wonder if maybe they never bothered to drain the block. With that possibility and my current situation in mind, approximately how much old fluid remains in the system and is it anything I should be worried about? I am hoping adding 4qts. of fresh coolant should dilute things enough. Thanks.

no_really

IANAE, but normally to "flush" the system, you attach a hose, and run water through the system - getting the freeze plug out is unnecessary. Some cars have a threaded hose attachment near the firewall where the coolant enters the heater core, or you can buy one to install there at a auto parts store. You let the water run out the lower radiator hose. To flush the radiator, you run the hose in at the top pressure cap, and let it run out at the bottom hose, as well. To be entirely thorough, I suppose you would remove the thermostat under the top radiator hose, and run water in there, as well.

apex2k

Thank-you, I might have to give it another go.