its not a standard size, its much thicker than a regular o ring. i went to take my old one off to sie it with another o ring, and instead of stretching off it broke into a million pieces.
i put a regular o ring temporarily but it was leaking because it was hardly touching the outer walls where it should seal. I ordered mine from toyota, napa or autozone should be able to get one for you, though napa was going to charge me 4 dollars to have it shipped to their store
