When building a 30's style hot rod, the usual Ford '39-'48 hydraulics may seem to be a bit too modern. But what to use instead? Hot rodders of the time either stuck with the stock mechanical brakes or switched to hydraulics from another manufacturer. Remember that Ford was nearly the only car still using a mechanical system by then. While yesterdays rodders just had to get to the nearest junk yard and scrounge for suitable brakes, the situation is different today. If you find any other brakes at all, they most likely will have to be restored and it's not at all certain that the parts needed are any easier to find.
On the other hand, a car that is amply supplied with brakes resto parts is the model A. But why not stick with the stockers and make them hydraulicly operated instead? Their somewhat bad reputation stems probably from the sensitive adjustment of the linkage. Badly set up, the car will veer off sideways when braking hard or maybe hardly break at all. Also, even if the linkage is serviced regularly, wear will sooner or later take it's toll and worsen the situation. The brakes themselves ain't that bad, they are big enough to stop a light weight hot rod if properly set up.
So, the goal was set, convert the stock A brakes to juicers. I made a trip to the nearest cheapo auto supply store and started tearing up parts boxes looking for wheel cylinders with suitable dimension. Well, I didn't attract attention from the store personnel and I found a cylinder that would fit. Namely, tadaa, '83-'87 Mazda 626. Yuck, jap crap! Yeah I know, but these were aftermarket and certainly not produced in J***n.
The first thing to do when installing these wheel cylinders is to remove the old mechanism. Remove the expander mechanism in the backing plate and the rollers on the shoes. The backing plates will then have to be modified with some new holes to fit the cylinders. I also welded in new hooks for the return springs (1). The brake shoes must be trimmed slightly to leave room for the cylinders. An advantage of these Mazda cylinders is that there are slots machined in the pistons. This makes it impossible for the shoes to slip off. Tabs made of steel plate were welded to the shoes on the outer side, this makes them line up perfectly in the drum (2). That's pretty much all there is to say, take a look at the pictures and remember that the increased power this setup allows is of no use if there are old worn linings on the shoes or the drums are badly worn.