Brakes

Model A Ford

Brake Handbook.

 

Part 1, Introduction:

 

The Model A Ford was originally designed with an outstanding braking system, given the driving conditions of the day. This was the first low cost vehicle to offer 4 wheel brakes, along with a separate parking brake system. The braking system was very safe and offered many thousands of miles of reliable service.

Unfortunately 80 years of wear takes its toll on braking efficiency. Most Model A Fords on the road today have never truly undergone a thorough restoration. Most have been serviced and repainted over the years. The brake system components are hidden from view under the car and were rarely maintained properly. The engine braking of a Model A is such that under normal driving conditions you may never really have to push the brake pedal hard to get stopped.

That is until there is an emergency. Then you may find out that the brakes are not what you may expect.

To understand what is happening when you apply the brakes, you must imagine all the mechanical things that are taking place underneath the car. Over 300 parts are called to service when you push the brake pedal. The brake rods are being pulled by levers and fulcrums. Shafts are turning inside bushings. Rods are being forced down into wedges that are driving the brake shoes apart. The force of the brake shoes is creating friction against the smooth steel drums.

 

Over the next few months, we’ll look at all the different aspects of the Model A Ford Brake System. The format will be such that you can collect each installment to create your own comprehensive Model A Ford Brake Handbook.

 

I’ll also post each segment on the website, in case you miss something.

Thanks and Happy Motoring,

Bentley C. Bohanan

Bentley’s Antique Auto Service, Inc.

www.mymodela.com


Model A Ford

Brake Handbook.

 

Part 2, “Do the Tighten Up”

 

The Model A Ford Mechanical Brake system is an excellent set up for the car it was designed for. Since it is a mechanical system, there are a lot of areas that really need attention to get the brakes back to their full operating potential.

 

Take a few minutes and check out the brake pedal, brake rods, brake rod return springs and Brake Cross Shaft. All these areas can be checked without any disassembly. Note: all Part Numbers are from Mike’s A-Fordable Parts catalog.

 

Brake Pedal: Grab the brake pedal and move it side to side. The pedal should have no side to side movement, and should glide smoothly in its down stroke when you push the pedal. The brake and clutch pedal have brass bushings inside, and a replaceable shaft on the transmission housing. Consider adding a grease fitting on the bottoms of the clutch and brake pedals for yearly lubrication. The brake/clutch shaft rebuild kit is available that contains the bushings, shaft, and pins under PN# A7505/09. Original style grease fittings are PN# A353027

 

Brake Rods: Check your brake rods for looseness at the clevis ends, bent rods, wear or damage, welded areas, missing clevis pins and missing cotter pins. Try to get as much slop out of the clevises as possible. Oversized clevis pins are available under PN# A2463. You will need a 11/32” reamer to open the clevises to the correct size for the oversized pins. Once the clevis pins are fitted properly, then use some grease on all the clevis pins before you put them back together. New Brake Rods are also available PN# A2499/B2864. Don’t forget the pedal to brake cross shaft rod. Make sure to re-install all cotter pins.  

 

Brake Rod Return Springs: These are also known as “Anti-Rattlers” They are available in a couple of different configurations depending on the year of the car. Make sure these springs are installed so they are pulling the rods towards the wheels. They are intended to be return springs, so they should be installed so they return the brake rods when you let off the brakes. If these are installed correctly you will rarely need any additional “helper Springs” installed on the brake pedal. New Brake Rod Return Springs/Anti-Rattlers are available PN # A2405/2866

 

Brake Cross Shaft: Unless you have a very early 1928 with the split brake system, then you have an arch shaped brake cross shaft under the center of the car. Get under the car on a creeper and grab the brake cross shaft. There should be no up and down movement on the brake cross shaft. It should rotate smoothly in the bushings. If the brake cross shaft is loose in the bushings then you probably need a rebuilt cross shaft available under PN# A2485E.  If you are handy with a welder and metal lathe you may be able to rebuild your own Cross Shaft. There are also Modern grease fitting kits for the brake cross shaft.

 

Once you have all of these areas working smoothly with no slop, you’ll be ready to move on to the next portion of the job: The Brake Backing Plates

 

Thanks and Happy Motoring,

Bentley C. Bohanan

Bentley’s Antique Auto Service, Inc.

www.mymodela.com


 

Model A Ford

Brake Handbook.

 

Part 3, “I’ve Got Your Back-ing plates”

 

If you’ve been following this Technical Series, we’ve been looking at the Model A Ford Mechanical Brake System. So far we’ve looked at the design of the system, and the Metal from the Pedal to the Road. Now we’ll look at the Brake Backing Plates, and see what we can do to get them in a restored or serviceable condition.  If you have missed any parts, you can see them at www.mymodel.com.

 

Most carport mechanics will remove the brake drums, pry off the old shoes, install a set of relined shoes, and put everything back together. This will result in a very disappointing brake job. The problem is that everything on the backing plate is worn, allowing the brake shoes to drop down so that the bottom of the shoes will constantly rub the brake drums, and the tops of the shoes are so far out that you will use all the travel of the brake pedal to get the shoes to contact the drum, and there is no leverage left in the system to apply any pressure against the drums to stop the car.

 

First, jack up the car and use jack stands to hold the car safely while you are working. Remove the wheels, and brake drums. You will need a hub puller to remove the rear drums. Go ahead and remove the backing plates from the car. You might want to do one side of the car at a time, so you can reference the other side as a blue print for reassembly. If you go ahead and remove the one bolt holding the front of the rear radius rods to the driveshaft tube, you will be able to remove those radius rods and easily remove the rear backing plates from the car.

 

Before disassembling the backing plates, keep in mind that there may have been asbestos linings on your car at one time. Therefore it is a good idea to thoroughly wash the assemblies before you start to work.  Use a dust mask when working with the dirty backing plates and parts.

 

Remove all the brake shoes, rollers and springs from the backing plates. Use a brake adjusting tool, or adjustable wrench to turn the brake adjustment wedge all the way in. When the wedge has turned in completely, you can tap it with a mallet to drive the dust cover out and remove the wedge. I like to rethread the wedge holes with a 9/16”-18 tap to clean the treads up.

 

Now there is a roller track on each backing plate. This is where the brake shoe rollers travel back and forth every time you apply the brakes. These tracks must be perfectly straight, so have them welded and ground back completely flat. If you inspect the tracks, you can see where the track was originally, so try to get them back as close as possible to original. If the roller track arms are broken, there are new roller track assemblies available.

 

The Rear backing plates have Camshafts that go through brass bushings. To remove these, you must drill out the rivet in the lever. Do this carefully so you don’t damage the lever or the camshaft. Remove the camshaft, then replace the brass bushings and ream the bushings to fit the camshaft. The cam should turn smoothly with no binding and no free play.

 

Once all the rework is done, I like to sandblast the backing plates and paint them with some gloss black enamel. This will make them look great on the car.

 

Next time we’ll move on to assembly and set up of the brake shoes and drums.

 

Thanks and Happy Motoring,

Bentley C. Bohanan

Bentley’s Antique Auto Service, Inc.

www.mymodela.com

Model A Ford

Brake Handbook.

 

Part 4, “All Together Now…”

 

If you’ve been following along at home, your Model A Ford mechanical brake system is all over your carport and work bench. Your brake rods have all been re-worked, your backing plates all look like new, so now it’s time to start putting everything back together.

 

First thing you will need are some new brake linings. These are available at Mike’s A-Fordable as either complete relined shoes (A2021RE), or linings (A2021), if you have the capability of relining the shoes yourself. Most Model A’s today use a woven lining. Be careful not to use linings that have a high metallic content, as they will tend to squeak against the cast iron drums. I have had no problems with the linings from Mike’s.

 

When assembling the brake shoes, there are rollers, clevises and pins that must all be installed in the new linings. Inspect each part to make sure there are no flat spots in the rollers, or worn areas on the pins. To be totally honest, if you do this brake job correctly, then you will not have to do it again for 50 thousand miles, so why not take the plunge and get new rollers and pins. It doesn’t add that much to the cost and you probably won’t have to do it again until 2047!

 

Same goes for your brake drums. I have reused original steel brake drums, but it’s really a false economy, when you consider the advantages of new Cast Iron Drums. The original steel drums were only 1/8” thick to start with, and after 80 years of use, they will end up less than 1/16” thick. This makes it difficult to get your brake shoes to fit up, and they get hot and warp, causing pulsing in the brake pedal.  New brake drums can be mounted to your old hubs, or new hubs are available if you need them.

 

Now that you have new drums, have the shoes arched to the drums. They should be a few thousandths smaller than the radius of the drums. This will allow the centers of the shoes to contact the drums first, and then make full contact as pressure is applied. Never allow the ends of the shoes to contact first, or the brakes will chatter badly. Also both sides should contact at once, or the brakes will squeak.

 

Next assemble your new shoes to the backing plates, with new return springs (A2035/36). Then use a centering tool (T2021T) to make sure the radius of the shoes align with the radius of the drums. This can be adjusted by bending the brake roller tracks slightly up or down to get the shoes in perfect alignment. Spend some time here for the best brake job.

 

Then you can assemble the parking brakes. That’s pretty simple, the only thing that goes wrong there is if the parking brakes have been used to stop the car, then the parking brake carrier will be all twisted up. New ones are available under PN# M1002 (left) or M1005 (right)

 

Now install the drums, with plenty of grease on the bearings, and new seals (A1175) for the rear. Torque the rear hub nuts down to 100 ft/lbs. Tighten up the front hubs nuts just enough to take the free play out of the bearings, no more. They should really be just finger tight against the bearings, them maybe one castellation tighter.

 

Next month we’ll finish this handbook with instructions on setting up all your brake rods, and adjusting the brakes. Like the old saying goes: “You’ll stop on a dime!”

 

For more information on Model A Ford Brakes, go to www.mymodela.com or get a copy of “The Model A Mechanics Handbook, Volume 1, by Les Andrews”. This is a great reference, and we have several copies with the covers about worn off in our work shop.

 

Thanks and Happy Motoring,

Bentley C. Bohanan

Bentley’s Antique Auto Service, Inc.  www.mymodela.com 678-407-1947

Model A Ford

Brake Handbook.

 

Part 5, “Whooa!…”

 

The final part of our brake job will be adjusting the brake rods, adjusting the brakes, and going for a test drive.

 

Your Model A should still be up on jack stands .The jack stands should be placed under the axles, with all the wheels at equal distance from the ground. All brake rods should be disconnected at the clevis ends. All clevis ends will point to the front of the car. The brake rod anti-rattlers should be installed so they are pulling the brake rods back towards the brake backing plates, to "return" the brakes.

 

First we’ll start with the brake pedal, and brake cross shaft. There is a stop on the back of the brake cross shaft connecting rod. This stop should rest against the cross member when the brake pedal is all the way back. I like to use a bungee cord to pull the brake pedal back until it just clears the floorboard, then adjust the clevis on the connecting rod to assure the stop is against the cross member. This stop will also trigger the brake light switch on ’30-’31s.

 

Now turn each wheel with your hands, the wheels should spin freely, with no drag from the brake shoes. Use an adjusting tool PN#T2041T to turn each brake adjuster clockwise. When the wheels are completely locked, then you are ready to continue the brake rod adjustment.

 

With the brake pedal all the way back, and the wheels locked with the brake adjustment, you can adjust the brake rod clevis ends. The idea is to shorten each brake rod as much as possible. This will assure you have adjusted all possible free-play out of the system. Keep shortening the rods until you can barely get the clevis pins installed.

 

Now back off each brake adjustment a few clicks until the wheels turn freely again. You’ll need to use the brake adjusting tool PN# T2499 “Brake Buddy” to make the final brake adjustments. Make sure each axle is adjusted the same, side to side, so the brakes don’t pull you to one side or the other on stopping.

 

Pull the parking brake back 2 clicks to adjust your parking brake rods. Pull forward on the rods and adjust the clevis ends so that the rods are as short as possible.

 

Make sure all the clevis pins are in place, with new cotter pins installed at all locations. There are 16 cotter pins in the brake rods, so check each one carefully.

 

Now for a test drive. Take your brake adjusting tool with you, and go down the driveway, stopping several times to check everything. Stop on a down hill and check the parking brake. It should hold the car securely with no creeping. Now go out on the road, make sure there is no traffic, and test the brakes. If the car pulls to one side, adjust the brake tighter on the opposite side, until the car stops evenly. You can also check the temperature of the drums after driving to make sure the brakes are applying evenly. 

 

Your Model A Brake System should now be vastly improved. You should be able to stop from 40 mph in about 100 ft. without any panic. The brakes shouldn’t fade, or squeak, or pull to one side or the other. Keep in mind they are still antique car brakes, and keep a reasonable distance behind the modern cars in front of you who have 4 wheel power discs.

 

For more information on Model A Ford Brakes, go to www.mymodela.com or get a copy of “The Model A Mechanics Handbook, Volume 1, by Les Andrews”.

 

Thanks and Happy Motoring,

Bentley C. Bohanan

Bentley’s Antique Auto Service, Inc.  www.mymodela.com 678-407-1947






Bentley's Antique Auto Service is a Full-Service shop specializing in Model A Fords. It is named after me, Bentley Bohanan. My friends call me Benny, you can too. We are located in Maysville Georgia, about 60 miles North of Atlanta just off I-85.

Bentley's Antique Auto Service can do just about anything to a Model A Ford. We have done many, many full frame-off restorations. We do brake jobs, steering rebuilds, anything to the running gear, glass, upholstery, body and show quality paint work, you name it. We also rebuild Model A engines, including the Babbitt work to our same high standards. 

We provide excellent service to our customers at honest, reasonable rates. We do not try to be the "Cheapest" shop around, but instead focus on First-Class work that we can be proud to give back to our customers.

You are liable to find 8 to 10 Model A Fords in the shop at any time. We keep 2 or 3 full restorations going along with several service jobs and a couple in the waiting room to be started on. Since Bentley's started in 1996, we have completed many, many full "down to the last detail" restorations. Several of these full restorations have gone on to win awards at local and National level car show competitions. We also do a lot of service jobs, which usually include brake and steering work, electrical, cooling system and so forth. Call or come by if we can be of any help to your Model A.

Some other services we can provide you:
Machine shop and welding services
Engine rebuilding including babbitt work.
Show quality paint and body work.
Individual assembly service and rebuilding, such as steering gears, brakes, rear ends, steering arm balls, radius ball replacement, etc...
Help with purchasing or selling a Model A.
Help with locating or selling used Model A parts.
Appraisal services for insurance purposes.


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