Home › Forums › Stay Dirty Lounge › Service and Repair Questions Answered Here › 2005 civic ex coolant leak › Reply To: 2005 civic ex coolant leak September 16, 2022 at 8:04 am #1001526 EricTheCarGuyKeymaster Be sure to clean the corrosion out of the bore before installing the new ‘o’ ring. Also, I use silicone paste on the ‘o’ ring before insertion to prevent it from being damaged when installing.