Does anybody have experience with testing and re-using engine coolant?
After a very long time I need to pull the radiator out of my Scout, get it fixed (leaky solder joints mostly) and refill. The old coolant (conventional green Prestone) looks reasonably good. The radiator is clean inside, the coolant is clear. Specific gravity is low.
New coolant is more expensive than I remembered, and getting rid (legally) of the old stuff is harder than it used to be. Simply adding more antifreeze to make the specific gravity correct is trivial, but I wondered if there might be more sophisticated tests to detect more subtle problems like pH. The original mix used distilled water, so total dissolved solids are likely to be OK. The major worry is the state of the corrosion inhibitors. Ordinary pH test papers are subject to cross sensitivity, so it'd have to be checked for use with coolant. Web searches for coolant testing found only specific gravity testers, nothing about pH or other chemical tests.
Thanks for reading, and any stories!