imported_janz3n

i searched but didnt get a clear answer. ever answer was a little different.
car is a 91 civic 4 door.
recently replaced the rotors and pads because the rotors were warped. a mechanic told me my one caliper was leaking but not bad. and recently after i did the brakes my pedal has been getting squishy and almost going to the floor but not all the time. and when it does if i pump them the pedal feels good again. theres still lots of brake fluid so i dont think im leaking any at all since its at the same level as it was when i did the brake job. i just want to know if this is a MC problem or if i just need my brakes bled. the fluid is really dark and could probably use a flush aswell.

imported_janz3n

i found a couple tests on honda tech to see if the MC is bad or not..and it seems to be fine. im gonna bleed my brakes.

imported_Cablerat

Brakes issues are annoying to diagnose for sure.

There are test for the Master Cylinder and Brake Booster. Search the forums here and honda-tech.. For example, while your car is on, press firmly on your brake pedal. If the pedal sinks to the floor it's pretty much your MC. It means the internal seals of the MC are worn and the fluid is blowing back into the resivoir.

Very dirty fluid will also cause soft pedals.

Also with Warped rotors, it's important to ensure you have a clean hub before putting them on. If you can, go buy yourself a deflection tool from princess auto. It's like a needle pointer you set against your rotor and then spin it. The needle will move in and out showing you warpage of the rotor.

My old rotors seem warped, one side had deflection of -10 to 20. The passenger side was 0-15. I took them off, cleaned off the hub, the inside of the rotor and re-seated everything clean. Doing so resulted in 0-5 deflection on both rotors and no more shaking.

imported_Cablerat

make sure you bleed in the proper order for your car.

Generally if you haven't exposed any lines to air or you have not had any leaks, you shouldn't need to bleed.. Unless of course you are so hard on your brakes that the fuild actually boils..

imported_chris_v2

may have high moisture content in your fluid.

But it sounds like you have air in the line.

imported_janz3n

i did about 4 different tests to check for a bad mc and all of them were good. which made me happy. im not gonna be bleeding my brakes myself , i'll see if i can get them done for free at work. or cheap at least. im gonna say the fluid has probably only been changed once in the whole cars life so its probably just due. my friends 91 sedan has a stiff brake pedal and i want one too.. im tired of this spongyness.

imported_janz3n

so i noticed today that when i downshift before braking making my rpms high the pedal doesnt sink at all or as much. is it possible im not getting enough vacume to my booster?

imported_janz3n

mechanic at work said i need a new MC , so im gonna see if an eg MC will work on my car becuase i can get one for free.

imported_chris_v2

maybe i read it incorrectly, but your pedal isnt supposed to sink when the rpm's rise..

imported_janz3n

the pedal will NOT sink as bad when the rpms are higher, but that could just be all in my head.