so i put new front pads on my 98 civic the other day, but i ran into some issues along the way (broken caliper bolt), so the drivers side caliper set with the piston out most of sunday day and all night until about noon monday. when i put everything back together i didnt have time to check anything out before work. so when i got home i started the car and went to put it in reverse to take it for a test drive, and the brake pedal went to the floor. so i pumped the brakes for about 30 seconds and it still went to the floor. i did not remove the brake line from the caliper nor did i remove the cap from the brake fluid reservore. any ideas at to why or how to fix?

 

When you say the piston was out do you mean removed? If so then thereis air in the lines.

 

no the piston wasnt removed. i broke a caliper bolt and the short version of the story is that i had to order a new caliper bracket so i left the caliper sittting on top of the rotor all night. so there were no brake pads there to keep the piston from extending all the way. when i tried to push it back in it didnt want to go then on the third try it went back in really easy. dropped the caliper back in place and put everything back together.

 

so i took the car to a shop today and the bled the brakes for $10, but they weren't able to get any more pedal pressure than what i already had. when changing the pads i noticed that the driverside seal around the caliper piston was cracked and they said when i pushed the piston back in i probably finished it off and to get new calipers so i did. then bled all 4 brakes in order and still nothing. what gives. what could have possibly gone wrong just from changing the pads?

 

The master cylinder may be bad.

 

although this is possible, how would it have gone bad by me changing the pads? the pedal was a little soft before i changed them, but i thought it was because of the lack of material left on the pads.

 

Did you bleed the brakes before putting the new pads in? I've seen master cylinders go bad from people not bleeding the brakes and trying to just push that piston back in (which can be done) with some pliers, but if you do it too fast you'll break the part.

 

Why auto parts go bad when they do often defies explanation. If your brakes are spongy after thorough bleeding of the hydraulic system, and you cannot find a fluid leak, the master cylinder is the prime suspect.

 

no i did not bleed the brakes prior to pushing the piston back in. never heard of doing that. i did it after i had everything reinstalled.

if i go to a bone yard to get a master cylinder what are the odds i will get a bad one? really dont want to spend $110 on a referb. and definately not $160 on a new one.

 

is there a way to tell if the brake booster is bad? i could be totally off, but i think its ok because i can pump up the brakes and get pressure but as soon as i start the car the pedal will go to the floor when depressed.