Will new coolant clean rust in an engine?

Jan 6, 2009
Watertown, New York
Silly question, but I have a 1957 Ford 860 tractor I am slowly fixing up.
The cooling system has pretty obviously been neglected. I replaced the thermostat and rad hoses and installed new Zerex green coolant.
When I had the thermostat housing off, I noticed it was pretty rusty in the housing and block.
I didn't dare use a chemical flush at this point because the radiator is pretty rough and I don't want to open up a leak.
Just wondering if the new Zerex might be able to clean any of the rust on it's own.
I know it's a long shot, I figure even if it does anything slowly , that would be a win.
It would take forever, even as your using a silica antifreeze. You may not want to 'open a leak' but a flush is the best way. If the anti freeze did pull any rust off that block, guess where it will end up.. yup, the radiator, and most likely clog it, making your issue work than brazing some solder on a few leaks.