Your brake system was repaired and or was not properly bled. There is a rather involved procedure to bleed this brake system and requires a scanner with ABS capabilities. Not an advocate of "take it to a dealer" but in this case, if you can't find a brake shop that knows how to do it(that you trust) the dealer is the only option. Your ABS system will not work in its present condition even if the brakes seem to be working fine. There are several places on-line that explain the procedure. Good luck!