Home › Forum › Ask A Member › 49 Champion – expansion plug? › Re: 49 Champion – expansion plug?
I’ve installed cup style automotive freeze plugs before, but this is my first attempt at this size and style. I’ll take all of the advice I can get.
Sounds like a welch plug to me, and it’s in the typical size range. I’ve never seen a welch larger than about 3/4", though they may certainly well exist.
Easy enough to install. Make sure the bore is clean, and there is no dirt or corrosion pushed up against the shoulder. Secure the workpiece well, set the plug in place, and secure it by dimpling the dome with a round, flat punch of the appropriate diameter. I believe the rule is to use a punch that’s 2/3 the diameter of the plug. Drive the dome in just enough to secure the plug fully, do not drive it so far that it goes below flush, and collapses inward or you risk losing the fit.
If you do goof up, drill a hole in the center of the plug, thread in a sheet metal screw, and use that screw to pull the ruined plug out. Try again with a new plug.