Brakes

[Standing Elk]

Ok, let me say right off that I am not disagreeing with the concept of proportionally setting up the brakes on the model A. However, I am the sort of guy who is not satisfied just being told something if I do not see the logic or fully understand why, so bare with me here. That being said I understand that you would not want your front brakes locking up before the rears and this is the reasoning or logic behind setting the rears up more than the fronts. But it seems to me, that since the front of the car has the added weight of the engine and will have even more added weight as soon as the breaks are applied, due to inertia, then there should not be an issue with all four breaks being set the same. So what am I missing here? Not saying I am right just trying to understand. Thanks

[Jacksonlll]

The model a was designed for rear skid. Modern cars are set up for front skid. Because of the weight, I don't think you could make the front wheels skid with the rear on a high friction surface.

[WHN]

I remember the first time I rode an English bike with front and rear brakes when I was a kid.

Coaster brakes were used on most bikes back in the day. “Rear brake only”.

For those of you that see where I’m going here. You know what happened if you gave it to much front brake.

Back brakes first, than front brakes. Most of the time, all you use is the rear brakes. Enjoy.

[SeaSlugs]

I cant explain why Henry had them setup that way but from a safety standpoint you DO want the fronts to lock before the rears so the rearend doesn't skid around and spin the car. If all 4 are set equally due to the inerta load the rears will lock up and skid.

When adjusting brakes ive been told and have done when you cannot turn the front wheels anymore the rears should still turn but be rather hard to turn with both hands.

Roads have a crown to them and if your rear wheels lock the rear of the car will go towards the ditch while the front goes into on-comming traffic. If the fronts skid you skid straight and eventually if skidding long enough into the ditch. If your on a curve good luck.

Modern cars are typically 70-30 split - meaning the front does 70% of your braking while the rear does 30%. Really modern cars all have ABS - the shortest distance you can stop a car is that moment right before the tire skids - abs pulses back and forth on either sid eof that moment so you still have control.

[Synchro909]

I'm not being critical in any way here but the way I see it, a driver will lose directional control over the car with the rear brakes locked no less than with the front ones locked. For maximum braking, front and back should reach the point of locking at the same time. Obviously once all 4 are locked, the driver is just there for the ride as he has gone past the point of maximum braking and has lost any ability to steer the car.
When the wheels lock depends on a few thing like load distribution, road surface tyres and more. Given that, we are kind of chasing our tails worrying too much about the details, IMHO. Whatever the case, Ford had too much bias towards the rear which was common practice in days when 4 wheel brakes were something comparatively new. It took a while to get things right.
I build my cars for driving and to do so as safely as I can in modern traffic and the idiots I am forced to share the road with. I move as much bias toward the front as I can but still haven't reached the ideal. I do that by improving the efficiency of the front brakes, not lessening the efficiency of the rear ones.
Let the debate begin! (politely)

[SeaSlugs]

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Originally Posted by Jacksonlll

The model a was designed for rear skid. Modern cars are set up for front skid. Because of the weight, I don't think you could make the front wheels skid with the rear on a high friction surface.

If you repeatedly kept driving on the identical patch of road (ie keeping friction the same) you could eventually find that sweet spot when adjusting the brakes to skid all 4 but in the real world with grit and ever changing road surfaces it would be pure luck.

[Bill G]

I am not sure I understand the question.

But, here is an answer any way.

The key part of the mechanical brake system that makes it so that the rears have more braking power than the fronts is the actuating levers at the ends of the brake rods. Front levers are noticeably shorter than the rear levers. About half as long. That gives the rear more leverage and more braking action.

You can always back off the back brake adjusters, thus biasing the power more to the front. Some folks have also put longer levers on the front to give more front bias.

I didn't want to mess with the original configuration because I am not ready to have the fronts lock up on me and loose steering. I had that happen in my Honda on the ice the other day. Not a fun feeling. Plus the Honda has ABS, but on pure Ice, that doesn't do much good.

[Standing Elk]

Ok, so now Magic's answer brings up another question. If Ford's intention was to bias the braking effect toward the rear by making the rear brake actuating rods longer, more leverage, then why is at least one "excepted way" of setting the brakes up also advocate setting the fronts looser than the rears, referring to the "notched brake stick" method?

[Keith True]

The bias is engineered into the brake system.If you adjust the brakes according to the service bulletins it will act the way it is supposed to.If you try to change the bias by adjusting you are going to be under adjusted on one end and over adjusted on the other.If you try to use the arbitrary system of the board the brakes can do wonky things.That board does not allow for a few thousandths wear here and there,or a few thousandths of bends in the parts.That board idea was a gadget invented by a tinkerer in the 50's,and some try to hold it up as the holy grail.All that board is meant to do is to show you where things should be at different levels of the pedal.The trouble comes when people try to adjust things to fit the board.If you adjust according to the service bulletins the adjustment will be right on.If it still doesn't stop right you have other problems.

[Bill G]

I think that the notched board is just a way to make sure everything is equal. If you start with the adjusters on all four wheels just shy of applying any braking when the brakes are at rest and the clevis pins are adjusted to also be just shy of applying any braking pressure, all four brakes are in theory exactly equal and just shy of braking with no brakes applied. The key point is that all are exactly equal (more or less)

You could stop adjusting right there. You are in theory all set. The rear bias is built into the mechanics.

When you use the board and go through the notches, all you are doing is confirming that all the whees are doing what they should be doing at any of those settings. I.E. Rears applied hard and fronts are applied lighter, or rears are locked and fronts are firm but not locked. My thinking is that these steps with the notched board are just fine tuning the biases that are already built into the mechanics of the system itself.

I think some here have said that they don't even use the board.

[Bill G]

Looks like I posted at the same time Keith True was posting. I think we are saying the same thing.

[1931 flamingo]

The adjustment process has been the same for 87+ years...........why try to re-invent it??
Paul in CT

[michael a]

Let me throw this in the game where do floaters come into play

Sent from my SM-J700T using Tapatalk

[Synchro909]

Originally Posted by 1931 flamingo

The adjustment process has been the same for 87+ years...........why try to re-invent it??
Paul in CT

Maybe because there have been improvements made in the mean time as understanding of the dynamics involved improved?

[1930-Pickup]

In those days many cars were driven mostly on dirt roads. Today not so much. Was the original adjusting procedure set up more for (slippery) dirt roads, or hard roads, or a compromise?

[NCRebel]

I have enjoyed reading the posts here. I think adjusting the "brake adjustment board" with a shorter first notch will give equal braking tension on all four wheels at once. I like the rear slowing before the front on my A because of the steering control in a quicker distance.

I crashed an early model motorcycle by pulling the front wheel brake before the rear. It was no fun for the machine either.

[Bill G]

Originally Posted by michael a

Let me throw this in the game where do floaters come into play

Sent from my SM-J700T using Tapatalk

Interesting question. I am sure many others know the answer to this better than me. The purpose of the floaters is to make brakes operate more efficiently, and I think they are more often installed on the fronts, because the stock rears actually do float. Seems to me that more efficient braking, particularly from the front, will probably add a little more front bias. Just my opinion.

[jb-ob]

A point always over looked in the discussion of why Model A brake design is the fact most of American roads were unpaved dirt when the car was new. Era road maps show pavement ending just outside of town.

The era design seems to support the idea that dragging dead weight from behind while steering from the front was most efficient.

Was this a 'carry-over' idea from two wheel rear Model T brakes and how far into the V8 years did the design exist ?

[Patrick L.]

Ford was just learning about 4 wheel brakes with these monsters and we've come a long since. There is a big difference between wedge brakes and self-energizing brakes.

The last I want with these monsters is for the fronts to lock before the rears. When these brakes are working and adjusted properly they stop quite well at the speeds these cars were designed to run at.

[glenn in camino]

I've been driving my Model As for 40 years, and I always adjust the brakes tighter on the rear and so I can just turn the wheels on the front. It's always worked fine for me.

[jb-ob]

Long before wooden planks, was the 'Pedatrol'

"Pedal Depressor Is Useful Tool"

"A new type of 'quick action' pedal depressor is a device for use when equalizing and adjusting the Ford four-wheel brakes. Not only does it prevent the loss of time which occurs when an extra mechanic is called from other work to hold the brake pedal depressed while the brakes are being adjusted; but it insures much more accurate work as the tool holds the pedal depressed steadily at an exact distance, which no mechanic is apt to do."

"Peters & Russell, Inc. of Springfield, Ohio, the markers of the Pedatrol, as the new pedal depressor is called, have worked out a new method of equalizing and adjusting the brakes which they call the Pedatrol method."

'Ford Dealer & Service Field, 1928"

The photo shows a ratcheting design, with one end on the brake pedal and the other on the lower seat bracket or riser. ( Also in the photo is the gear shifter lifted and pulled out of it's usual position.)

[Tom Wesenberg]

I'm pretty sure we are all going to crash, burn, and die, unless we all change to hydraulic brakes.

[Flathead]

Not just hydraulic brakes but hydraulic DISC brakes with a dual master cylinder. Anything less than that is a certain death trap according to today's "experts". I saw a t-shirt that said "I'm a six volt guy living in a twelve volt world" think about that.

[Keith True]

I do have to say that the board way of adjustment has made me quite a little bit of money.The best one was a 30 Fordor with over $2000.of parts in the new brake system.He had adjusted it right to a T with that board.He was a little put out with me because I kept telling him to get that stupid board out of my face.He told me over and over again that I HAD to us it to adjust the brakes. adjusted it the way it was supposed to be done when it was built,and I told him to take it for a ride.He never came back that day.His buddy told me he was mad because some 60 year old kid had fixed his brakes in 35 minutes and he had rassled with them for months.When he did show up a week later to pay me he never asked for his board,and I didn't bring it up.It is still in the shop.

[Purdy Swoft]

I mostly agree with post 9 and 24 . Don't try to change the configuration of the system . Set the brakes up as detailed in the service bulletins . There is no mention of an adjustment board in the service bulletins . Correctly setting up the pedal rod and service brake cross shaft with the pedal at the top of its travel is very important. Then remove all slack from the service brake rods and the brakes will be ready to activate with the slightest touch of the pedal .

As for floaters . Floaters help to center the shoes to the drum . Complete contact of the shoes to the drum when the brakes are applied is important . The shoes have to be at least pretty close to centered after installing new lining or the drums won't fit over the shoes . Modern cars don't have this problem because the brakes are full floating .

Cast iron drums are one of the best improvements to avoid brake fade . Flathead teds square centering pins can help center the brakes without the need to build up or replace the brake tracks . The square pins have 4 different height settings .

[CWPASADENA]

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As originally designed, Our Model A's had apx 40% of the total braking on the front and apx. 60% on the rears. This was a definite improvement over the Model T which only had rear wheel brakes. Thru the 1930's, as brake dynamics became better understood, Ford changed the design of the brakes on the vehicles they manufactured where the fronts did more braking than the rears. Ideally, the bias of a Model A Ford should be some where in the order of 60-70% front and 30-40% rear.

To improve braking on out cars, more brakes should be added to the front without reducing rear braking effort.

Floating wedges will add some brake effort to the front which is a step in the right direction. These have been around for almost as long as our Model A's have. They are very easy to install and there is definitely an improvement with their use.

Increase the length of the front levers will also add brakes to the front. A few of us are doing this with very good results. 50% longer levers and Floating Wedges will definitely add brakes to the front and change the bias closer to where it should be where more braking is on the front. To my knowledge, you would have to make your own longer levers as I do not know of anyone manufacturing them.

Installing Ted's Floaters to the fronts is another way to add more brakes being to the front. However, it is absolutely imperative that the front brakes be properly set to get all the benefits from Ted's Floaters. There is very little latitude in the available adjustment with Ted's Floaters and if everything is not absolutely correct, there will be little if any improvement.

Replacing the front brakes with 1932-'34 (12 in. dia.) front brakes is also a way to add more braking to the front. This is a direct bolt on installation that does not require any modification. The larger '32-34 brakes along with floating wedges will result in a very good system with overall braking biased close to where it should be.

Just keep in mind, which ever modifications you may chose, the whole brake system must be in good condition in order to realize the potential improvement. Trying to add fixes to a worn out system will result in not little if any overall improvement.

As a Mechanical Engineer with many years in the automotive industry and a Road Race Car designer, builder and driver, it is common knowledge that a front engine automobile needs to have the braking bias designed so more braking is on the front and less on the rear. Also, we know that you do not want the rear brakes to lock up before the fronts. When this happens, the vehicle has the tendency to very quickly swap ends. That is why, race cars often have an adjustable brake bias control where the driver can change the brake bias depending on track conditions, fuel load etc, but the driver never wants the brakes biased where the rears to lock up first.

NOW PLEASE UNDERSTAND, These comments are based on my education and experience and I do not expect anyone to agree with me. Every one must proceed in a direction they feel right for them.

Chris W.

[Synchro909]

CWPASADENA, you echo my thoughts exactly. Those who want to leave their car "as Henry made it" are quite welcome to do so. I, on the other hand place greater importance on not only my own safety but that of my passengers and other road users.the judges
I don't know how judges would handle a car with say, longer levers on the front over there but judges I know here would regard them as a desirable safety measure and not deduct points. Just like turning indicators don't cost points or a second tail light or.....or......

[BILL WILLIAMSON]

Then WHY was it common practice, for EONS, to set all the system in PERFECT SYNCHRONIZATION & all brakes APPLYING at the same time????
Weight transfer WILL cause the REAR brakes to skid, FIRST!!!
I "think" I just heard Chief (RIP) LAFFIN' about the BOARD!!!
Bill Practical

[WHN]

As always, some great comments.

But please keep in mind the following.

Thinking has changed on braking a lot in the last 90 years. Also tires, suspension, shocks, springs, weight distribution, steering control, on and on.

A Model A Ford that is mechanically correct. Brakes, front end, springs, shocks, steering, will handle very well.

Is it the right car to run on Interstate 95 running through Connecticut with traffic doing 75 to 80 mph. NO!

I would not want to lock up the front brakes on our Model A before the rear brakes. This is not a race car. Car was not set up for that type of braking. The buckboard suspension could bring the rear end right around.

I would hope anyone who changed braking system would inform new owner when selling of what had been done. Some of us might not see that as an up grade. Enjoy.

[CWPASADENA]

Originally Posted by WHN

As always, some great comments.

But please keep in mind the following.

Thinking has changed on braking a lot in the last 90 years. Also tires, suspension, shocks, springs, weight distribution, steering control, on and on.

A Model A Ford that is mechanically correct. Brakes, front end, springs, shocks, steering, will handle very well.

Is it the right car to run on Interstate 95 running through Connecticut with traffic doing 75 to 80 mph. NO!

I would not want to lock up the front brakes on our Model A before the rear brakes. This is not a race car. Car was not set up for that type of braking. The buckboard suspension could bring the rear end right around.

I would hope anyone who changed braking system would inform new owner when selling of what had been done. Some of us might not see that as an up grade. Enjoy.

You are correct to say that the Model A is not a race car but the same principals that apply to designing brakes for a race car also apply to road cars. For a front engine car, you need more brakes on the front than the rear. Ford also figured this out in the thirties when they designed their cars with more bias to the front. This was still at the time when the new Fords in the later thirties still had "buggy springs", straight axles and antiquated lever shocks.

The Model A brake system was just the first step for Ford in the evolution of designing 4 wheel brake systems for their cars. In the perusing years Ford added more front brakes until the bias was more to the front.

Better brakes on our Model A's are not useful only for highway driving but also around town when it is necessary to make an emergency stop when someone turns in front of you or a small child runs out in the road in front of you.

I feel my cars with improved front brakes are a lot safer to drive than any "stock" Model A with properly restored non modified brakes. More than once, I have found myself in a n emergency situation where a vehicle pulled out in front of me from a side street and I was glad I had improved brakes that allowed me to stop without being involved in a collision.

If the Model A brakes were perfect as designed, why did Ford just a few years later change the design of their brakes to more front bias, and why did aftermarket manufacturers make kits to improve front braking shorty after the first Model A's were sold?

Again, I am not saying than anyone should modify their brakes, that is up to the individual owner. I am saying, "if you want better brakes on your Model A, add more brakes to the front", this is a definite improvement.

Again, this is just my opinion, others may have a different opinion which is fine with me.

Chris W.

[WHN]

Chris:

You are correct in that Ford did change their braking in the years following the Model A.

They also changed the size of the tires, steering, and how the car sat.

I am not saying that the Stock brake system from the factory is the best you can get. I am saying that once you lock up the rear wheels, the fronts, if adjusted properly, will lock up shortly after. Narrow tires, not much tire/ground surface. Wheels not turning, what more can you do.

On a light, high center of gravity car, with narrow tires. Lock up the front tires, and watch what happens to the rear end. Also the center of gravity will shift giving even less weight on the rear wheels.

In almost 60 years of driving these cars I have only locked up all four wheels a couple of times. Car did not move off track, but did skid further than I would have liked. “Tires”.

Coming up with new ideas is what we pay you engineers to do. Keep the ideas coming.