Need to change the coolant on the Foci, noticed there is a drain plug but from what I can see of the O-Ring it's very perished and afriad it will leak when I start messing about.

Does anyone know what size they are? Or if you can get replacements from ford etc?

Also heared these engine can be a mare of air locks. Would I be better off just emptying the expansion tank, filling it up with neat coolant and doing this a few times?

MK1 Focus 1.6.

Bailes.