I appreciate your response. However, it doesn't explain the need for copper.I believe it has to do with attaining the proper torque, and being able to seal properly without the chance of unscrewing.
You'll find copper washers for the connections between brake lines and and calipers/wheel cylinders as well.Sump drain plugs are the only place I have ever seen these copper washers used. I was just curious why that is.
Of course, this is all academic. The manual says to use a copper washer, so a copper washer I will use![]()
2008 Passion, 86,000 miles, 12 oil changes, original washer, no problems.FWIW, many of us continue to use the original washer at each oil change, with no leaks. YMMV, of course...![]()
Part of the reason may be that copper has been used because of its malleability since the 1930s for certain items, and the fact that it resists corrosion of the type that would affect other materials available at the time.I appreciate your response. However, it doesn't explain the need for copper.
If it is a matter of sealing, then there are lots of materials with superior sealing properties.
If it is just a matter of proper torque, no washer should be necessary. The gearbox drain and fill plugs have no sealing washers and are torqued to a much lower setting without risk of unscrewing.