spongey brake pedal?

[Boagie]

Hey guys,i seem to have a spongey brake pedal...the brake fluid has'nt dropped and the wheel cylinders don't seem to be leaking.Any ideas what causes a sudden spongey pedal???

[growler2058]

I've got a similar thread somewhere??? And it's anything between being a stuffed master cylinder or stuffed proportioning valve. I'm hoping master cylinder in my case as I've bought one and it's waiting for me to get home and fit Friday ;-)


Tap, Tap.......Who's there?

[Robo]

vac booster can also cause this.
a shim or something can drop off inside and causes a spongy peddle according to a manual I have.