'58 leaky brake cylinder

[Little Girl]

I'm getting brake fluid in the Vacuum portion of my brake cylinder assembly and it's dripping down the control rod. I have changed the seal between the hydraulic and vacuum sections and the square o ring above it.  Anybody have an idea what might be causing the leak?

[Little Girl]

I've taken it apart again and the leak seems to be at the gaskets between the hydraulics on top and the vacuum chamber below in the same place it was before I replaced those seals. The pressure when i checked the brake action unseated the o-ring and let the fluid leak down into the vacuum chamber.  The pedal action is very stiff now and I had previously been having problems with the brakes dragging intermittently which is why I took the damn thing apart in the first place.  Does this sound familiar to anyone?

[Little Girl]

OK, so the rubber cup seal in the master cylinder seems to be split on it's inner edge.  I hope I have solved the mystery

[J. Gomez]

Is yours Bendix or Moraine?

The Moraine M/C has two seals; the one inside the plug is primarily the vacuum seal, not 100% sure on the Bendix but it would be the one before the leather seal.

Good luck…!

[Little Girl]

I've got a Bendix. I'll let you know how it goes

[Little Girl]

I ordered a rebuild kit from Old Parts Source on e-bay. A new piston cup seal did the trick and my brakes are working properly now. As an added bonus, my brake pedal now comes all the way back up without assistance from my toe
Rose