i have an 89 civic lx. idk why it does this, but whenever I drive my car for a little bit and I'm pressing the brakes pretty often, they do engage, but for some odd reason they dont disengage until i either shift into a higher gear and practically floor it until they give, or shut my car off for like a minute. i replaced the calipers, wasnt it, and replaced the master cylinder, didnt fix it. when i first got the car, i had my friends dad change the brake booster, which i heard might be the problem, or could be the lines. im guessing because of the heat, it expands and stops it. its annoying because i feel it in the brake too.
for example, if i just start driving my car after it's been off for the night, the brake pedal will move about 4 inches easily. but wen the brakes start to rub, i can move it maybe half an inch, probably less. thats it

anyone have an idea what could be the problem?

 

Find out which wheel is dragging, that is simple to do by driving a little (don't overdo it) while dragging and then check for excessive heat at the brakes. If it's just one wheel try replacing the hose to that wheel. They can get restricted, it's not a real common problem but considering you've replaced almost everything else.

 

they're both dragging. so should i replace the hoses for both? and which hoses? the whole line?

 

Since both drag, also check first that your booster is properly adjusted. The easiest thing to do is loosen up the stop nut on the booster under the dash and maybe also the brake light switch so the brake pedal can go up higher. See if that resolves the problem.

 

where is the stop nut exactly located?