I have been noticing that my brake pedal is spongy. What I mean by spongy is that there is a good bit of travel with no real braking, then I need a significant amount of pressure near the bottom to get "normal" braking. I didn't really notice it until I drove my wife's Miata back-to-back. I did a gravity bleed of the lines and it didn't help any. Any thoughts? Awhile back I took some of the fluid out of the brake reservoir and replaced it with new (thought about trying to swap all my fluid this way before I did the gravity bleed). Maybe I got some air in there?

I am not the most mechanically inclined, but I do know that I followed the instructions exactly to do the gravity bleed.

Anyway, just thought I would see what you guys thought is the problem. If it is very likely air in the lines, then I will just have them bled by a real mechanic.

 

pump the pedal a tonne then put full force on pedal, if it starts to move then you gots air in the system.... otherwise if the hydraulic system is good then it could be worn pads in comparison to new pads?

There aren't any leaks or whatever near lines, calipers and master cylinder?

 

Do this check

Start the car and release the E brake, stay Neutral

Press the brake and HOLD it down.
If u feel the pedal still going down while u holding a steady pressure on it, the brake pump is bad/going bad

If you feel bounciness within the hold and release your brake fluid could have been in there too long (and got too much moisture) or you have air in the system.

You should replace your brake fluid on a yearly basis for tip top braking pedal performance.

 

first thing first you can start by flushing the old fluid out, while you at there, check to see if there's any leak(MC, caliper, lines, etc)

when you do a complete fluid, it's a good practice to do a bleed again after a fee days of driving, most of the time there's some bubbles still trapped in there.

if you are not sure about the procedure have it done by a pro, the brake is the last place you want to mess with esp when you are not exactly handy with car(which is okay)

if you recently boil the fluid, you should replace/fluid the whole system, boiled fluid will have a much lower boiling point.

 

What year is the car? How much pad do you have on it?