i have a 99 ranger sport 2wd. lately its been going through brake fluid about every 3 weeks. i notice my ABS light comes on, i check the fluid, it's about half empty, i fill it, light stays off for about 3 weeks and then the light comes back on and fluid is low again. i can't tell if the MC is leaking or not. i don't notice any braking problems, it stops perfect every time. what should i replace? also, what price range am i looking at if i take it to a shop?