Brakes work but you have to push the pedal all the way to the floor. have refilled DOT3 brake fluid 3 times, it stays on the "minimum" line----never goes dry. Brake light is on, went off momentarily after the first refill of fluid but now stays on all the time. Car has 74K miles (low miles for a car this old.) No problems with brakes ever, until just now.
So what do you think it could be? first time to this forum, as well as first posting.

 

Welcome !
From what you describe, it sounds like you have a definite leak somewhere in the brake hydraulic system. Until you or someone else finds it , It's probably not a good idea to drive the vehicle until the leak is found and corrected.
That leak could be anywhere from one of the wheels ,hoses or brake line from the master cyl. You should never have to add brake fluid unless some parts are replaced where fluid is lost. As brake pads wear the level in the master cyl will go down and this is an indication of attention needed to pad replacement. You have been fortunate that the problem has not become worse where you could lose considerable braking power. Look under the vehicle for any type of leak starting at all the wheels then where the brake lines and hoses are.

 

if it has drum brakes you should open the drums and have a good hard look at the wheel cylinders.

 

You are in good hands with hanky and bluewind in your corner. As with everything there are many options locating the problem source. I would personally do the following.

Take a paper towel and wipe off the top of the master cylinder (where you fill the brake fluid) and under it where it bolts to the brake booster.
Look under the car paying close attention to the inside of the rims, make a mental note of how things look, hopefully dry.

Start the car and pump the brake pedal a couple times, then smash hard on it and hold a few seconds, 10 to 20 that is.
How does it feel, hard, spongy, is it going down or staying firm where it is?

Shut the car off and look around the master cylinder, is it wet? Look under the car at the inside of the rims, are they dry? While looking at the rear you can see the back of the drum, is there fluid dripping from it? While looking at the front you can see the calipers, the brake hoses, and the line connectors, are they dry? Look on the ground forward of the rear axle, any fluid there?

Have faith you will find the leak.

*edit: Warning… brake fluid and paint do not mix, be careful to keep your hands clean and not allow the fluid to make contact with your painted surfaces.

 

right rear brake hose leading to the wheel is shot. Leak leak leak. Should be a cheap fix. This is the kid's car......still happy with it! thanks all.