brake felt sponged even with new brake pad and bleeding?

[heyzerg77]

My braking always felt sponged, and it requiring hard effect on braking.
so I decided to replace the brake rotor and brake after they all worn out.

But My braking still felt sponged even with new brake rotor and pads.
I bleeded the brake as well with ATe Blue fluid
My rotors are Ate power disk and brake pad are PBR metal pad.
but My brake didn't felt sensative as it should be. since I felt sponged on my brake pedal.

What could be wrong?

[rs4pro3]

Master cylinder or still air in the lines.

[Beej '86 325es]

Master cylinder or still air in the lines.

Mine always has as well, even with the S.S. brake lines. I never thought about the master cylinder being bad, that must be my problem.

[rs4pro3]

ussualy when the master goes bad the brakes don't engage till the floor. After I replaced the master in my 318i when it went out the pedal firmed back up.

[MattM20]

if the master cyl was leaking it would take a pump or two to gain full firmness, and if it was blown, the pedal would go right to the floor. if you dont have to pump your brake pedal and still consider the brakes spongy even after a brake job, then a 25mm master cyl is what you need.

[heyzerg77]

Could I use post 88 master cylinder on pre88 325e

Thanks for the reply.
I just wonder if i could use post 88 master cylinder on pre88 325e,
Would it be a better uppergrade?

thanks.

[Beej '86 325es]

if the master cyl was leaking it would take a pump or two to gain full firmness, and if it was blown, the pedal would go right to the floor. if you dont have to pump your brake pedal and still consider the brakes spongy even after a brake job, then a 25mm master cyl is what you need.

That describes mine pretty well. At first push, it's spongy, but if I let off and push right away again, it feels pretty good. Would this be an external leak or something internal so the whole thing would have to be replaced?

[demlotcrew]

A correct method of bleeding results in plonged life of the MC, you shold not push the pedal past the normal travel distance to make sure that the seals in the MC dont get screwed.

:arrow:

[E30godz]

right when i did my brakes/rotors and bled the brakes, the brakes felt shitty.

but after a several miles (probably 20+) they started feeling fine again

[e30evolution]

if getting a new master cyl either get and e30 m3 master cyl
or a 750il master cyl