im going threw the same thing my brakes grab sometimes and then sometimes dont but im changing mine out today, its most likely your cylinder or possibly the booster and most auto parts stores have a core charge, it shouldnt be 80$ its more like 40$ if you bring in the old one, its around 75 if you dont but its a dumb decision to not take it back your gonna throw it away anyways, but i could be off thats the price of a cylinder for a 92 integra with abs,