Posts Tagged ‘1928-31 Model A Ford brakes’

Mounting the C4 Corvette Vacuum Assisted Power Brake Booster in the Hot Rod

Thursday, January 12th, 2012


Mounting the C4 Corvette Vacuum Assisted Power Brake Booster in the Hot Rod

Well, the festive season of Christmas and the New Year with lots of visiting, good food, and entertaining has come to an end. We only had one major snowfall in our area. For the last few days the weather has been sunny and usually warm. It will be a good feeling getting back into the shop and continue working on the 1929 Ford roadster hot rod. With the shop warm and some great classic rock tunes the environment will be perfect for working on the hot rod.

The frame mount for the C4 Corvette vacuum poer brake booster on the 1929 Ford hot rod.

The time has come to install the C4 Corvette vacuum assisted power brake booster in the 1929 Ford roadster hot rod. When I originally designed the chassis / frame for the hot rod, I decided it would be a great idea if I could incorporate as many of the C4 Corvette parts removed from the 1986 Corvette Indy Pace car convertible as possible into the custom build of the custom Model A Ford roadster. Basically my intention was to have a C4 Corvette disguised or cloaked as a Model A Ford. So, it made sense to use the entire braking system including the vacuum assisted power brake booster with the master cylinder. I did decide early on in the chassis / frame design to mount the brake booster and master cylinder on the chassis just underneath the driver’s seat. The power booster is a bit larger in diameter then most aftermarket booster available for custom hot rods. This is not much of a problem, as the 1929 Ford roadster hot rod using the C4 Corvette suspension will have the chassis / frame sitting a safe distance from the road surface. Basically the 1929 Ford roadster hot rod will be a high boy design using modern suspension.

The heim joint used for the C4 Corvette vacuum power brake booster.

The power brake booster and master brake cylinder are a fair distance to the brake pedal assembly. After a considerable amount of thought, I decided to use a 0.75 inch (3/4”) round steel shaft to make this connection. A heim joint was used to connect to the brake pedal assembly. This part was easy. All I needed to do was drill a hole on the metal lathe in the end of the shaft so that I could tap the hole using a 0.375 inch ( 3/8”) NFT tap. The outer diameter of the heim joint was almost the same diameter of the 0.75 inch (3/4”) extension shaft making this end very neat and tidy.

The adapter coupling for the C4 Corvette vacuum power brake booster

The heim joint attached to the pedal assembly

The C4 Corvette vacuum power brake booster with the shaft extension.

Not wanting to modify the shaft coming out of the C4 Corvette vacuum power brake booster, I had to come up with an idea of connecting it easily to the extension shaft. After sleeping on it for a few nights, and just looking around the shop a bit, I realized that some 0.75 inch (3/4”) square tubing could be used as a coupling adapter. A small amount of material was removed from the round extension shaft using the metal lathe so the shaft would fit into the square tubing coupler. Using the MIG welder the square tubing was welded to the round shaft and trimmed up on the metal lathe. To connect the vacuum power brake booster to the coupling and extension shaft a two small shims were use on either side of the brake booster shaft and fitted tightly inside the square tubing. The extension shaft with the newly made adapter was bolted to the brake booster shaft. The newly modified power brake booster with the master brake cylinder was bolted to the chassis and the brake pedal. Of course I needed to get in the hot rod and try the brakes out. As expected everything worked smoothly.

The C4 Corvette vacuum power brake booster mounted to frame / chassis of the 1929 Ford hot rod.


Designing a brake pedal assembly for the1928 – 31 Model A Ford

Monday, December 19th, 2011


Designing a brake pedal assembly for the 1928 – 31 Model A Ford

Many years ago I started with a couple of vintage Plymouths. One was a 1930 and the other a 1931. Both were four door cars. I bought both of these cars for $3500 as the seller did not want to split them up. Maybe the cars had an attachment to each other, who knows? This seller was bit different. He had so many cars and projects, that one person could not finish them all in ten life times. He told me that he could part these cars out and make a fortune. This guy had lots of ideas and stories but a lack of time or maybe interest. This is the usually pit many car builders fall into. Collect lots of stuff, but never do anything with it because they are too busy collecting stuff!!! The 1930 Plymouth was hanging from the ceiling on chains in his shop so he could pack more cars in the building. I must say there was an interesting collection of cars.

1934 Plymouth brake pedal used in the 1929 Ford hot rod

A few weeks later I sold the 1931 Plymouth for $3200. Now I was into one car for only $300. The 1930 Plymouth had numerous parts I did not need for the hot rod build so they were all sold via eBay and local advertising. The fellow I bought the cars from was bang on about selling parts from these cars. I guess he didn’t have the time or interest to do what I did.

The vintage Plymouth brake pedal breaks

More money just rolling in and I really haven’t started the build yet. Over time I realize the 1930 Plymouth was not for me and I sold it and finally ended up with the 1929 Ford roadster body. In the process, I bought and sold several cars and kept parts I thought I would need for my build. I did keep a brake / clutch pedal assembly from the 1930 Plymouth and another one from a 1934 Plymouth.

Designing the new brake pedal for the 1929 Ford hot rod.

When I designed and built the chassis / frame for the 1929 Ford hot rod, I welded a bracket onto the side of the chassis / frame for the 1930 Plymouth brake / clutch assembly to bolt to. Now it came time to install the brakes. Everything fit as it should except the brake pedal needed a few adjustments. It needed to be shortened slightly. I cut it at the bend and removed what I needed to, and re-welded it with the addition of a gusset for additional strength. Of course I thought it would be a great idea to sit in the roadster on a milk crate and give the brake pedal a try. Just a big kid at heart!! Well that didn’t work out so well and maybe a hidden blessing. One of the brake pedal parts broke along the keyway slot were it attached to the shaft. This could have been deadly if the car was out on the road. I even attempted to repair this part and it broke again. It was then I decided to design and build my own brake pedal assembly. There would be nothing worse than driving a car you cannot stop.

The new brake pedal taking shape for the 1929 Ford hot rod.

Using the slightly altered original pedal as a template, I traced a pattern onto 3/8 inch steel plate. This was then cut out on the metal band saw and the edges sanded smooth on the 1 inch belt sander. A small shaft collar was then welded to the pivot point of the brake pedal. I reused the shaft form the vintage brake pedal assembly in my new design. At the time, I did not have a lathe or milling machine so I needed to use my imagination to fit pieces together with materials I already had.

The first fitting of the new pedal on the 1929 Ford hot rod.

Now I traced the base plate onto 0.25 inch steel plate so my new brake pedal assembly would match the bracket already welded to the chassis / frame of my 1929 Ford hot rod. Using some scraps left over from the lower control arms mounts for the lower control arm I made the mount for the brake pedal shaft. A couple of bronze bushings and grease fittings were added to minimize wear of the rotating parts.
Everything was assembled and bolted to the 1929 Ford hot rod for a trial fit. I noticed a minor adjustment would be required on the lower part of the brake pedal. Once this adjustment was made, the new brake pedal assembly was primed and sealed.

The completed new pedal assembly.

The last thing I needed to do was fabricate a new brake pedal pad. Again I traced the original vintage pedal onto 3/8 inch steel plate. A small mounting bracket was added so the pad can be bolted to the pedal. The face of the brake pedal pad will eventually have a piece of ribbed aluminum attached to it to give it a more finished look.

The new brake pedal pad for the 1929 Ford hot rod. The new brake pedal installed on the 1929 Ford hot rod.

Oh, I forgot to mention. The brake pedal parts from both the 1930 and 1934 Plymouths were sold shortly after completing the one I designed and built. I tend sell or give away anything I do not see a future use for as I do not want to be a collector of stuff that I will never use.