Best brake pedal for a 1947 Ford, when going to 4-wheel disc?

Question

I am in the process of upgrading my 1947 Ford to 4-wheel disc brakes. I currently have the stock pedal and master cylinder. Front brakes are stock and have a Ford 9-inch in the rear. I have the kit for the front disc and one for the rear disc, Do not know what to do for a master cylinder. I am not sure if power is the way to go either.

thanks Mike

Answer 1

You need to change to a dual chamber master cylinder if the original is a single chamber design. Most of the pre-70 cars are single chamber OEM. I just did a front conversion on my 55 Buick and it had a single chamber.

you'll also need to change the metering valve/proportioning valve. I don't know if you got one with the kits but they have to match your new design. A metering valve applies fluid first to the rear brakes to overcome the return spring pressure on rear drum brakes; then allows pressure to the front disc brakes to equalize braking force at each wheel. If you go to 4 wheel disc and have a metering valve on the car you'll lbe applying the rear brakes before the front and that could cause the rears to lock up or wear out faster. A proportioning valve is used on 4 wheel disc and distributes the pressure front/rear based on caliper piston size and brake force distribution so that the car brakes evenly and in a straight line.

I don't know where your master cylinder is located; if its on the firewall it should be pretty easy to find a dual chamber master cylinder that will fit. The propotioning valve can be from any newer vehicle of similar weight with 4 wheel disc. You can also buy adjustable proportioning valves that are a pain to dial in. You'll have to do the research on that.

if the brake master cylinder is under the car as it was on my buick, then its going to be harder to find a dual master that will fit without cutting a hole in the floor as I had to do. You may want to try some car club sights or try
www.hotrodders.com
to see if anyone has had specific experience with the 47 ford. if you do post to those sites, they'll want to know specificaly what model it is, whether its a car or truck, etc.

hope that helps.