Spongey Brakes

[MaxBell]

Hey guys;

I've got a problem with my E30 M50 swap's brakes.

I've replaced the master cylinder with one that is known to work, there are no holes, it's been fully bled. The booster is good, as far as I know.

However, the brakes are still spongey and don't lock up at all.

What gives? Is there too much vacuum from the M50? I have the valve in there properly...

Should I just run a delete plate and be done with it?

[bmwstudent]

excessive vacuum assist will not cause a spongy pedal. I don't think you could generate "too much vacuum." I know you said its fully bled but it sounds like they aren't.

[Adrian_Visser]

Bleed and then bleed some more. It takes a bit less than 100ml iirc to bleed the right rear caliper (furthest from mc) so bleed that much from each corner and you're golden. I thought I had my brakes good the first time and I still had to re bleed after the test drive.

[MaxBell]

Shitty, ok I'll get back to bleeding them :( I need more friends to help bleed brakes!

[jlevie]

Shitty, ok I'll get back to bleeding them :( I need more friends to help bleed brakes!

Well, that is one way, but with a pressure bleeder it becomes a one person job.

[DaButt]

Well, that is one way, but with a pressure bleeder it becomes a one person job.

+1 to the Gospel of Jim.

Pressure bleeder makes it full-retard easy.

[MaxBell]

The answer I'm leaning towards is that the booster cleavis needs to be moved out to let the brakes engage sooner.