Does anyone know if the Phoenix Systems visual test strip is accurate? and if so how accurate?
Well, yes and no. The strip measures the amount of copper in the brake fluid. In that sense the strips may be considered accurate.
The presence of copper in brake fluid is supposed to indicate that corrosion inhibitors are used up. The problem is that no one really knows how much copper must be present to suggest a flush is necessary. One group of automotive specialists has declared that 200 ppm copper is the standard for fluid repacement. The auto manufacturers have not, to my knowledge, confirmed this statement.
So there you go, psbriggs. Make up your own mind. As always, caveat emptor.
there is a better way to deal with brake fluid. get two quarts, and use the bottle method to bleed brakes. pump a quart and a half through the system, alternating brake calipers, thus flushing all the fluid out, and cleaning the system, and then viola, , you have new brake fluid!! no worries about whether your brake fluid is good or bad!