Coolant Flush 冷却水交換

I've tried a radiator flush on my car for the first time. Radiator flush costs about $80 in store, so it is much cheaper to do it by yourself. It is easy, but takes time. When I was about to fill in a new coolant after draining the old coolant, flushing and cleaning the system, I mistakenly broke the drain plug by tightening too much...... Fortunately, the coolant itself doesn't seem leaking at all because the top part of the plug is still stuck inside. I must be really careful for overheat now.冷却水交換を自分でやってみた。店でやってもらうと８０ドル位かかるから、自分でやると６０ドルもセーブできる。初めてだから入念に調べ、父にも手順を聞き、すべてが順調に思われたんだけど、最後にやってしまった...　ドレンコック（冷却水を抜くキャップ）を強く締めすぎ破壊w　不幸中の幸い?で、壊れて中に残された部分がラジエーター漏れを防いでいるから車は動かせるけど.......