Since DOT 5 is not recommended for ABS brakes and I frequently tap into my "race" fluids for the street cars/trucks I do not keep in around. Use DOT 4 but not for the higher boiling point but because you can get it in colors so that you can readily tell when you've flushed out the old and replaced it with new. Any way it goes you need one of these:
https://www.turnermotorsport.com/p-3...-fluid-tester/