So, I replaced master cylinder, brake lines, brake pads and brake discs.

I bled the master cylinder, followed by the rear tires then the front ones. Up until now I'm certain that the old brake fluid has been drained out.

I meticulously bled each brake and I'm certain that there are no bubbles and the brake that squirts out of the line is new (used to have a brown color).

Yet, I still have "spongy" brakes and the pedal, when pressed, goes all the way to the bottom.

I searched this forum and read my Haynes book (not to mention that I read my carfiche) to make sure that I've done everything the right way.

Am I missing something or did I do something wrong?

 

are you sure you still have fluid in your cylinder, when I was bleeding my clutch, I would get to the point where no air was coming out, but it wasn't getting better, and pretty soon I realized I had accidentally drained out all the fluid, then I'd have to start all over, and then I kept bleeding too much. Finally I'd bleed once, or twice then check the reservoir.

 

n00blar, are you bleeding the system by yourself? If so... get someone to press the pedal while you open & close the valves. Also, re-bleed the master.

 

you didn't put calipers on upside down did you? i did that once wow did it take forever to figure out nobody could catch it....

 

Yes, still fluid in the master cylinder

No, I'm not bleeding brakes by myself. I have my son pumping the brake pedal 3 times and then holding it down while I bleed that brake line. Yes, I bled the master cylinder yesterday again...and still nothing. And yes, it has plenty of fluid.

No, calipers are in the right position.

I just checked for any leaks in the break lines, since I replace those, and all seems clean. I also checked for leaks in the master cylinder lines and nothing was wet.

I'm starting to believe that I have a defective master cylinder; what do you guys think?

Oh, and one other question: why do you have to start with rear brakes in the bleeding process?

 

Does the master Cylinder make a squishy noise when your son depresses the pedal? (like fluid running past the rubber seals)? Did you inspect all your rubber lines looking for bubbles or soft parts that swell up when pressure is applied to the system?


Usually you bleed the longest runs first than the shortest.

 

Hmm, I haven't noticed any noise, but I'll check that.

What rubber lines are these that you're mentioning? Brake lines perhaps?

 

The rubber lines are the ones that run from the metal brake lines to the caliper. You know... these:



n00b - either the master is defective, or there is air in the lines somewhere... those are the two possible probs.

 

bleed the master lots, make sure your kid pushes really slow, if he pushes quick, it just creates more air. do the right rear first, then move to the next closest caliper. tap the caliper near the bottom with a large wrench or small hammer to help the air go to the top. also tap the master when bleeding to do the same. keep at it, and your not running the car while bleeding are you? some ppl do, and you shouldnt, it may seem all so simple but i gotta ask.

 

...Not the ONLY two...

Caliper seals, bleeder valves... all kinds of other stuff could be sucking air and not showing a visible leak...


Rod.

 

Indeed you are correct... you make me ask thus:

n00b, was the brake system working before you replaced the master & brake lines?