Hydraulic Brakes

[700rpm]

Originally Posted by Mike V. Florida

Then there is nothing we can say except, some people never let facts get in the way of an opinion.

Good point, Mike.

[Pete]

Originally Posted by Jim Brierley

I have hydraulics on 2 of my A's, and would never go back to originals, especially on a driver. I use silicone fluid, no leaks and doesn't draw moisture. They are 1" bigger in diameter and have wider shoes. Lincoln type are self energising = easier pedal pressure. They were designed for heavier cars so give you more stopping power in reserve. Sure mechanical's will slide stock wheels and work fine at low speeds and no traffic, but your life is at stake. Don't take chances. If possible drive someone's stocker to get a feel of mechanical's and ask how often they need adjusting.

I'm with Jim.

Joe K has it right about the size of the tire patch. Not very big on a model A.

Here's some data to digest. While not under lab conditions, it was measured as close as a surveyors tape could do.
I rigged up a device on the front bumper of my A that would shoot a blank cartridge loaded with white chalk when I pressed the brake pedal.
I drove 30 mph on dry concrete, hit the brakes with a modulating force
as any driver who has been trained in maximum braking procedure should, and when stopped, measured the distance from the chalk mark to the front bumper device. After 4 runs I averaged the distance. 23 ft.
Doing it this way takes the driver's reaction time out of the formula.
My A has hydraulic 4 wheel disc brakes.

Now let's hear how some mechanical brakes do.
Just a tip, if you lock the brakes you will not stop in the shortest possible distance.

[Purdy Swoft]

The comparison of four wheel disc brakes and drum brakes are not the same as compairing Hydraulic drum brakes with mechanical drum brakes. Disc brakes will also outperform hydraulic drum brakes. All that I can expect my mechanical brakers to do is lock the wheels if applied firmly enough. If I don't want the brakes to lock, I apply less pressure to the pedal. As for mechanical brakes, a lot of people have non locking rear brakes. My point is that the model A is not a heavy car as compaired to modern cars. Steel drums can expand and fade under severe conditions for sure .Cast iron brake drums have been available for the model A for many years. Ford even introduced cast iron drums sometimes in 1931 . The method of activation doesn't cause drum hydraulic brakes to be superior to drum mechanical brakes. The size of the drums on the model A are large enough to lock the wheels. People that know nothing about brakes automatically figure that hydraulic activation is better because modern cars use hydraulic . If a person can't work with simple mechanical brakes, they are less likely to be able to bleed and work with a hydraulic system that will fail way befor mechanical . activated brakes .

[Synchro909]

Originally Posted by Mike V. Florida

Then there is nothing we can say except, some people never let facts get in the way of an opinion.

Mike, what facts are you speaking of???Seems there are plenty with pre conceived ideas that they won't allow to get in the way of an opinion! It doesn't take much brain power to realise that a 16" tyre has a larger area in contact with the road and therefore a better grip than the original ones, to say nothing of the more advanced design of radial ply tyres. If my Model A as a similar sized "footprint" on the road to a modern car, it could stop just as quickly so long as the brakes are capable of stopping the wheel turning which will take more braking force than an original would, hence my scepticism about the original brakes being able to stop a 16" wheel. Then there is the larger brake drum to wheel diameter ratio to consider. Larger drums on a small wheel will work better than small drums on a large wheel, like original. My scepticism is based on my doubt that an original brake could stop a "sticky 16" wheel turning on a dry road. PS I realise that a sliding wheel will not stop as quickly as one that is not. Maximum braking comes when the wheel is just turning and it is here that the strongest brakes are needed.

[pooch]

The mechanicals have 60 % rear and 40 % front.

They have not got a snowball's chance in hell of out stopping hydraulics .

As has been stated , the maximum stopping power is the most power put to all four wheels without any of them locking up.

By the time the mechainical rears have almost locked, the front are doing just a piddly amount of work.

If the mechanicals were 60 % front and 40 % rear , then that may make a difference, but they are not.

If they were so good, we would still have them on cars now.

[Pete]

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Originally Posted by Purdy Swoft

The comparison of four wheel disc brakes and drum brakes are not the same as compairing Hydraulic drum brakes with mechanical drum brakes. Disc brakes will also outperform hydraulic drum brakes. All that I can expect my mechanical brakers to do is lock the wheels if applied firmly enough. If I don't want the brakes to lock, I apply less pressure to the pedal. As for mechanical brakes, a lot of people have non locking rear brakes. My point is that the model A is not a heavy car as compaired to modern cars. Steel drums can expand and fade under severe conditions for sure .Cast iron brake drums have been available for the model A for many years. Ford even introduced cast iron drums sometimes in 1931 . The method of activation doesn't cause drum hydraulic brakes to be superior to drum mechanical brakes. The size of the drums on the model A are large enough to lock the wheels. People that know nothing about brakes automatically figure that hydraulic activation is better because modern cars use hydraulic . If a person can't work with simple mechanical brakes, they are less likely to be able to bleed and work with a hydraulic system that will fail way befor mechanical . activated brakes .

Boy, that was long winded to say essentially nothing.

"The comparison of four wheel disc brakes and drum brakes are not the same as comparing hydraulic drum brakes with mechanical drum brakes."

That's a crock. The whole thing has to do with energy transfer to the road surface, not how it is done.

You yourself said later that the method of activation makes no difference and that is true for the subject at hand. (model A's)
At 30 mph or just about any speed a model a is driven, discs or drums will make no difference. The activation system won't either.

As far as people working on their brake system, VERY FEW are qualified to even inspect let alone do maintenance work on them as noted by the many questions on this thread and other forums.

As far as maintenance, non self adjusting hydraulics will go 50K miles with no problems. Not so with mechanicals. They do not leak either, if assembled PROPERLY by a QUALIFIED person.

[29spcoupe]

I'm not convinced that the original brakes, no matter how well set up would be able to lock the 16" tyres on a dry road.[/QUOTE]

I locked up the mechanical brakes on my model t in heave traffic once. Pulled back the hand brake, stomped on the pedal, and heard the tires screech. Kept me from rear-ending the car in front of me. Mechanical brakes if set up properly are fine. John

[MrBruce]

I don't agree that the Model A drivers don't know anything about their brakes. The one's that don't rely on those of us who do. We have a tune up session every spring and everyone gets their car checked and especially if they are concerned about stopping. Those of us who drive our cars on the freeway and at speeds higher than 45 mph especially watch our brakes and keep them adjusted. It doesn't take that long when you keep them in shape every year.

[Purdy Swoft]

Originally Posted by MrBruce

I don't agree that the Model A drivers don't know anything about their brakes. The one's that don't rely on those of us who do. We have a tune up session every spring and everyone gets their car checked and especially if they are concerned about stopping. Those of us who drive our cars on the freeway and at speeds higher than 45 mph especially watch our brakes and keep them adjusted. It doesn't take that long when you keep them in shape every year.

Mr. Bruce, I agree some of us do understand the model A brakes . I am certainly not the only one. As I grew up with model As, The other model A guys were always ready to help other model Aers , even to the point of getting in and pulling the wrenches. Many even would give parts to ethers that needed them. Things have changed . In many cases its a different class of people that are quickly taking over the hobby .

[mshmodela]

Tires and drums would break the same given the same amount of force applied to them hydraulic or mechanical system. Force is force, if hydraulics applies more force than a mechanical system one might reason hydraulics would break better but there has to be some force limit where no extra force upon the breaks will do any good.

[Purdy Swoft]

Originally Posted by mshmodela

Tires and drums would break the same given the same amount of force applied to them hydraulic or mechanical system. Force is force, if hydraulics applies more force than a mechanical system one might reason hydraulics would break better but there has to be some force limit where no extra force upon the breaks will do any good.

I agree, when the wheel locks, it would make no difference even if more pressure could be applied.

[Synchro909]

Originally Posted by 29spcoupe

I'm not convinced that the original brakes, no matter how well set up would be able to lock the 16" tyres on a dry road.

I locked up the mechanical brakes on my model t in heave traffic once. Pulled back the hand brake, stomped on the pedal, and heard the tires screech. Kept me from rear-ending the car in front of me. Mechanical brakes if set up properly are fine. John[/QUOTE]

The original brakes might lock up the original tyres but if you had been following the thread, we are talking about the 16" wheels with more grip Even then, it took you both the ordinary brke AND the handbrake to lock up the wheels

[29spcoupe]

I merely used this illustration to show that mechanical brakes can lock up tires. You probably know that the Model T brake is totally different than the Model A. The Model T does not have front brakes and the service brake is on the tranny. But I can see now that I am dealing with someone that knows infinitely more than I. John

[pooch]

Originally Posted by 29spcoupe

I merely used this illustration to show that mechanical brakes can lock up tires. You probably know that the Model T brake is totally different than the Model A. The Model T does not have front brakes and the service brake is on the tranny. But I can see now that I am dealing with someone that knows infinitely more than I. John

And I bet only the rears locked up .

[CWPASADENA]

NOW!!!!!

If you want better mechanical brakes. Find your self some 32-34 mechanical front brake assemblies and install them on your Model A.

I have been told they are essentially a bolt on installation. The 32-34 fronts are 12 in. with cast iron drums.

This will not only give you better brakes on the front but it will get the front-rear bias better. The original Model A brakes were 40% front, 60% rear. The bias needs to be closer to 60% front, 40% rear.

I recently purchased another Model A. The engine, trans rear end, steering and suspension are all good but the brakes are worn out. I have a very good set of 32 mechanical brakes. I want to install the 32 fronts on the front and rebuild the rears using cast iron drums.

I may eventually also install the 32 brakes on the rear but there are modifications required.

It will be interesting to see how this works out.
I will keep you posted.

Chris W.

[Jim Brierley]

for CW Pasadena, 1935 brakes would be even better, they have wider shoes than the v32-34 brakes. I still prefer hydraulics -

[tbirdtbird]

do the '32 brakes on an A require a different length actuating pin? (the verticle pin)

[FlatheadTed]

If you check out my web site you will see the 16" wheels locking up Ted

Originally Posted by Synchro909

Mike, what facts are you speaking of???Seems there are plenty with pre conceived ideas that they won't allow to get in the way of an opinion! It doesn't take much brain power to realise that a 16" tyre has a larger area in contact with the road and therefore a better grip than the original ones, to say nothing of the more advanced design of radial ply tyres. If my Model A as a similar sized "footprint" on the road to a modern car, it could stop just as quickly so long as the brakes are capable of stopping the wheel turning which will take more braking force than an original would, hence my scepticism about the original brakes being able to stop a 16" wheel. Then there is the larger brake drum to wheel diameter ratio to consider. Larger drums on a small wheel will work better than small drums on a large wheel, like original. My scepticism is based on my doubt that an original brake could stop a "sticky 16" wheel turning on a dry road. PS I realise that a sliding wheel will not stop as quickly as one that is not. Maximum braking comes when the wheel is just turning and it is here that the strongest brakes are needed.

[waxhead]

Synchro, I have recently installed new cast iron brake drums and the Deluxe Dead Stop Brake Energizer Kit from Flathead Ted to enhance my mechanical brakes. I have 16x4 Kelsey Hayes wire wheels installed on my pickup with Firestone 650x16 Bias ply tyres.

https://www.cokertire.com/650-16-fir...blackwall.html

I installed the energizer kit and cast iron drums to the front first, as recommended by someone (cant remember who). I took the car for a drive and managed to lock up the front brakes/wheels without a problem.

I have also installed the kit and new drums to the rear of my pickup. All 4 wheels can now be locked up. My braking is now a huge improvement over what it once was.

I have adjusted my brakes so that the front brakes engage before the rear brakes.

I cannot say for sure that you will have the same outcome with radial tyres and a wider contact patch with the road, but this has been my recent experience with upgraded mechanical brakes.

Good luck with your brakes, regardless of which way you decide to go.

[hardtimes]

Originally Posted by Pete

I'm with Jim.

Joe K has it right about the size of the tire patch. Not very big on a model A.

Here's some data to digest. While not under lab conditions, it was measured as close as a surveyors tape could do.
I rigged up a device on the front bumper of my A that would shoot a blank cartridge loaded with white chalk when I pressed the brake pedal.
I drove 30 mph on dry concrete, hit the brakes with a modulating force
as any driver who has been trained in maximum braking procedure should, and when stopped, measured the distance from the chalk mark to the front bumper device. After 4 runs I averaged the distance. 23 ft.
Doing it this way takes the driver's reaction time out of the formula.
My A has hydraulic 4 wheel disc brakes.

Now let's hear how some mechanical brakes do.
Just a tip, if you lock the brakes you will not stop in the shortest possible distance.

Hey Pete,
Yeah, I'm with Jim also !
After reading his book and giving brakes some serious thought, I sold my entire 'restored' mechanicals to a Montana restorer and put an entire new system of Lincoln hydraulics on my '30 roadster. Being as the roadster is the lightest A and given that the Lincolns ('39 thru '48) were some of the heaviest American cars ...ever, I felt that Jims' advice was sound. They work very nicely and I will not be going back !
And, just remember that safety is paramount with todays traffic and with most guys wanting more horse power out of these A/B engines. I read here , all the time, of guys touting the freeway speeds that they are able to attain with their warmed up banger engines. Doubling or more the horsepower.. without .. upgrading the braking systems, is asking for trouble, IMO.