1957 Dual Master Cylinder Upgrade?

[Coupe Deville]

How do you bleed one of these systems? The pedal on my 57 goes to the floor right now. Car sat for a few years. Any ideas?

Thanks

-Gavin

[Walter Youshock]

Booster may be shot.  You first bleed the booster, then the wheel cylinders.  Start at the fitting on the top of the booster, then the one on the lower part of the booster, then farthest to closest wheel cylinders.

[Coupe Deville]

Does the booster run on vaccum at all? Or just hydraulic? Does the original master have a risidual valve built in? I wonder if fluid rolling back into the master is common because of the wheel clynders being higher than M/C. I just need to get the car out of the driveway and too my house.

Thanks for the quick responses.

-Gavin

[Walter Youshock]

Yes, the large chamber to the rear of the unit against the firewall is the vacuum chamber.  Basically, depressing the pedal forces fluid from the master into the booster where the fluid unseats a check valve allowing the vacuum within the booster to force the fluid back out to the cylinders under pressure.

The master doesn't have a check valve. 

[Coupe Deville]

Is there a procedure for removing a rusted bleederscrew. The bleeders on the booster are not stripped but rusted. I really don't want to snap them. Any ideas?

Thanks

-Gavin

[Walter Youshock]

Soak them with PB Blaster?  Really sounds like it's time to have the booster redone.

You CAN bypass the booster by running the line from the master directly to the brake line distributor on the frame.  Chances are you won't have any power assist or very little even if you can bleed that booster.