would you believe, my 96 civic is still using the same radiator it came with from the factory?
only top tank changed due to a crack in the plastic tank which was leaking radiator slightly. other wise never opened.
always used coolant no matter what. no overheat no problems till now.
avoid K seal. it will plug up an small holes.
the first thing that needs to be done is to actually check the radiator for leaks. this is done by blocking the lower hose.
and fill the radiator with air with an adapter for the top cap. then dip it in water and observe for bubbles. this is how its done at the factory that manufacturers radiators.
to test coolant, fill up prepared coolant in a bottle, and leave it over night in the freezer. if it freezes then the coolant is bad. if not, then its good to go.
the rust in your radiator is not from corrosion of the radiator. the original radiator was aluminum with plastic top and bottom. aluminum does not corrode like copper or iron.
the rust is from the engine block and engine liners. the corroded iron from the liner is deposited in the radiator causing it to choke.
mechanic will never tell you the proper method, other wise he will think that he will be out of a job.
coolant is always factory filled in engines, be it a tiny engine or a massive engine. plain water is poison for the engine.
