dr bob

Sorry. TSP is "trisodium phosphate" in a powder form. It was a popular cleaning agent in the past, included with many laundry detergents too until a decade or three ago. Farmers were found guilty of using high-phosphate fertilizers, so a blanket ban on most uses was implemented. Seems the stuff causes massive algae blooms in rivers when it runs off there. Anyway, there are some less-than-equal equivalents in the market for cleaning, none exactly as good.

For a casual use by DIY, a generous spray of oven cleaner will do the work of some caustic soda or lye products. OK on the plastic bits, but keep well clear of all aluminum with it.

GregBBRD

Keep in mind that brake fluid is water soluble.
Keep the solvent based cleaners away from the reservoir and clean with water soluble cleaners.