answer:If your coolant still has it’s green color, and your car isn’t over heating, I don’t know that I would bother flushing it right now. Especially with the possible issues involving the head gasket. I don’t know necessarily that the flushing would worsen or effect that leak, but I don’t think it’s really worth the risk. Now, once you have the head gasket issue resolved, I would almost certainly flush it, to ensure that there’s no oil or gas or what have you in your coolant system as a result of the gasket. If you want to check for things in your coolant, just pop the hood and look at the coolant everytime you stop driving. It’s constantly streaming through the engine while you drive, so the coolant you’re looking at will always be different. You’re looking for any kind of sludge, discoloration, metal shavings.. basically anything other than the green coolant itself. If you find anything like this it would definitely support the head gasket leak “theory.” Though it could also be symptomatic of another issue with your coolant system.