Hydraulic Brake Conversion

[8EL]

I don't have any experience with this particular application but in regards to the wheel cylinder orientation, I suspect that the important consideration is the relationship of the larger piston to the direction of rotation of the brake drum rather than the actual front of the vehicle. Therefore, swapping sides would not be an option but rotation of the backing plate and wheel cylinder to any location on the proper side would be acceptable.

The hydraulic brake offered much improvement in braking effort over the mechanical brakes that equipped the model A when new.
Ford used Lockheed style brakes from 1939-1948. They employed a wheel cylinder located at the top of the backing plate with different size pistons (unlike Bendix), the larger of the pistons actuated the primary shoe which had the longer lining of the two shoes. This primary shoe faced forward, and so did the large piston, this is the consideration, that the large piston acts on the primary shoe.

So then we come to the problem of the shock mounting ball and clearance for routing the brake line. To increase this clearance, in some instances the backing plate was rotated forward, while others placed the wheel cylinder on the bottom, or 180 degrees from its original mounting. This would place the large piston rearward facing as well as the primary shoe. By swapping them side to side the relationship of large piston and primary shoe to the front is maintained, and so was also done. The main drawback here is that this places the bleeder screw on the bottom making proper bleeding very difficult.

Rotating the backing plate forward introduces a problem with the emergency brake cable and the obtuse angle introduced opposing the otherwise straight line pull afforded originally.

Mounting it on top solves the problem with the emergency brake cable and the bleeder, but presents a line clearance routing issue.

I have attached the work around I have used to solve the brake line rout problem, and will be forming a new emergency brake cable raceway to solve that problem. As far as re-drilling holes vs cutting the necessary relief in the backing plate for the spring mounting strut, I consider this a wash, as they both require about the same effort. I am still waiting to see and example of the line routing taken with the cylinder on the top at 0 degrees from vertical.

I do not see a common sense virtue in cutting off the shock mounting ball to gain clearance for line routing. As this leaves the issue of having to engineer a new means of providing the function lost. I can not say that I have witnessed very many of these cars with modern shock over the originally equipped type.....Hope this helps.....

 

[8EL]

Here is a current pic of it. We really enjoy riding around in it.

Nice machine Robbie, a 31 like mine. It is exceptional that you have the lineage of this car. Most of use have no idea of how many hands ours has passed through in the last 90+ years. They are not fast but extremely tough and reliable little cars. They were like the model T, also affordable to the common working man....Not hard to see why they were so successful then, and still around in such numbers today.

I refer to mine affectionately as the tortoise, and my 63 Oldsmobile Starfire as the hare. This reference gotten as the Olds sports a 800+ horsepower supercharged V8. When I misbehave with the Olds, which is very easy to do (but so much fun), I put her away for a while and drive the much more sensibly conservative model A.

 

[Malibob]

This is just the post I have been looking for.

 

[Planojc]

Would like to see how you did your master cylinder.

 

[Flathead]

Maybe I'm mistaken but I thought cylinder could be rotated to the bottom, switched side to side and turned so the bleeder is at the top of the cylinder and big piston points the right way. I thought that this modification was known?