Hi, I'm a novice with cars so forgive me if this is a dumb question! My son brought his 96 civic in to a national chain for brake repair and they replaced his brake pads and calipers (and left axle). A few weeks later, he now tells me that he's been having trouble with his brakes ever since then, he went back to have his oil changed and they now say he needs to replace the master cylinder. It seems awfully coincidental - could they have done something to the master cylinder when doing the other brake work?

 

What is he saying the brakes are doing?
Is the fluid in the reservior in the correct range?

Considering they replaced the calipers...the brakes may need to be bled. Air might be in the system from the lines being disconnected from the calipers.

Shops like that may try and take advantage of the naive. After basic things have been checked, or if you guys cant, I would consider taking it to a different place for a 2nd opinion.

 

This exactly.

But first run a couple tests.
What happens when you press your break peddle down all the way when the car is on? Now try when the car is off.

 

if they bled it using the push the pedal to the floor then they could of cracked the seal in the master or if they just pushed the caliper back in it forces he fluid back through the master and can cause the same thing. places like jiffy lube, meinike, and places like those might do brake jobs that way.

like said above me if the brake pedal gos all the way to the floor when the car is on or if at idle the pedal sinks the master is bad.

when the car is off if you push the pedal and it firms up like a normal pedal but when the car is on and the pedal gos to the floor then the brake booster or master could be blown.

 

like the previous posters said they may have to be bled

 

I always Had weird hydraulic problems when replacing brake pads with my 93 civic. After the pad replacement the brake pedal would slowly drop when sitting still. Release the pedal and mash it down and the actual braking force was fine. Just really unnerving to have the pedal drop .

Only thing i Could figure is that on an older master cylinder, there will actually be pitting and corrosion outside of the master cylinder piston's regular travel area. So when you change the pads the piston moves in this pitted area and causes weird issues.

I replaced the master cylinder and it went away permanently.

 

Changed my rear calipers, pads and rotors and found the same problem. Changed master cylinder and now my brakes are fine. 97 DelSol