BIG Problem with my brakes

[R_CK_R]

Hi Guys,

I got a big problem with my brakes. Had almost the same problem 1,5 yrs ago... If my Car is rolling my braking pedal is going slowly to the ground but if my car stands still the pedal does not move.
Last time I fixed it with a master cylinder kit. This time I tried just to bleed the brakes but it didn't work.
Do you have any ideas what my Problem could be?

Season starts soon and my car has to run.

PS: All wheel cylinders are dry.

Greets Kai

 

[RPM]

Sounds like a new master cylinder is in order.

 

[Old Iron]

Sounds like a new master cylinder is in order.

X2^^^^^^^^^^
Yep prime symptoms of a bad master.
I'd get another master cylinder this time.

 

[MercuryMac]

R_CK_R, I agree with these guys. Brake fluid is leaking around the master piston and rubber cups, back into the reservoir. Quite often, it's the rubber cups that get scored or cracked and then leak. Sometimes, though the cylinder bore gets corroded and new rubbers won't stop the fluid from sneaking around the piston. A new master cylinder is the answer. I don't know why your brake pedal stays up nicely when you are not moving.

 

[R_CK_R]

R_CK_R, I agree with these guys. Brake fluid is leaking around the master piston and rubber cups, back into the reservoir. Quite often, it's the rubber cups that get scored or cracked and then leak. Sometimes, though the cylinder bore gets corroded and new rubbers won't stop the fluid from sneaking around the piston. A new master cylinder is the answer. I don't know why your brake pedal stays up nicely when you are not moving.

Ok thanks! I also asked the guys from classic Olds forum and got the same answers. So I think I have to order a new master cylinder.
Maybe is a little scratch in my master cylinder which destroys my rubber cups inside...