Hey guys,   56 Mercury has a single master cylinder and a vacuum booster, not sure if the booster is stock or not (don't really even understand how it works).  Need to replace the rear wheel cylinders this winter, as they are leaking a bit, didn't know that until the single master ran out of fluid, real fun...   Looking to put in a new dual master cylinder while im at it.   Should i be replacing the booster too with a combo kit?    Heres whats in the car now.


Heres what im looking at. - https://www.speedwaymotors.com/Dual-7-Inch-Brake-Booster-Master-Cylinder-Combo-1-1-8-Inch-Bore,36378.html

stock same as 5 6 7 birds used. my exp is they have short life,hard to get parts hear in canada, but they help when serviced

You'll need a 1" bore one and the mount, assuming the Merc is the same as Ford in its brake cyls  , . And it wont do you much good if your other parts are worn and most certainly if you have incorrect size linings etc.



"Came too close to dying to stop living now!"

From what I can tell, there’s 3 possible options on a 56 Merc. A “field” installed Bendix unit, and one of 2 sizes (early and late production) of a “Tredle Vac” unit. A picture of what you’ve got will really help. The tredlevac’s are a pain and expensive to rebuild, and the ones I’ve worked on used bell cranks and other odd linkage from the pedal to the booster. It wasn’t fun to replace it without a kit engineered by someone who knew what they were doing.

The Speedway example is fine, but that’s really aimed a a street rod build where you’re building a complete system. Having done that on several cars, you really want to determine what you’ve got and find a replacement designed for your car. Mixing even just the master and booster on 4 drum brakes is a different thing than drum/disc or disc/disc. If you know the engineering you can do it, but I’m not that good.

miker
55 bird, 32 cabrio F code
Kent, WA
Tucson, AZ