cast iron drums

[robert shreveport]

If you are going to change to cast iron drums can you change just the front and good results.

[Special Coupe Frank]

Stock Model A brakes have 60% of the braking effort going to the REAR wheels...

If you were just going to do one axle, I guess the rear axle would be the one to do...

[Kurt in NJ]

I am doing just the fronts on my car, my front drums were cut, and are out of round, my rear drums had no wear when I replaced the original linings ---I feel a little more braking from the front wheels will be an advantage ---this was Fords first high production car with 4 wheel brakes, modern cars do much more than 50% of their braking with the front wheels.

[ctlikon0712]

I'm not arguing the point, just wondering..... Why does everything I see concerning adjusting the brakes show to bias the rear first?

Still learning...

[Special Coupe Frank]

I've considered doing one axle at a time, as I don't feel I can afford to spring for four drums all at once...

We'll see...

[Special Coupe Frank]

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Originally Posted by ctlikon0712

I'm not arguing the point, just wondering..... Why does everything I see concerning adjusting the brakes show to bias the rear first?

Still learning...

That is the way the Ford Model A system was designed, in terms of the geometry of the operating levers...

The rear brakes apply first, then the fronts.

This is opposite of how drum brakes have been set-up since about WW II (60% front / 40% rear).

As Kurt mentioned, this was the first Ford with 4-wheel brakes; previous Fords ( and most other cars / trucks ) only had brakes on the rear wheels and/or the driveshaft.

At that time, there was an unholy fear of having brakes on the front wheels, on the theory that if you locked-up the front wheels, that took away their steering ability... this was still a concern when the Model A was designed, and they designed the brakes to have the rears apply first, followed by the fronts.

You really can't change this much without modifying the brake operating levers up front. And most Model A-ers don't feel it necessary: well-maintained stock brakes are quite effective.

[kenparker]

Hi Robert. To some degree your question will depend on the condiion of yur REAR brake drums. New cast front drums on front will help some, but if your rear drums are shot (less than .110 thick) you have lost a great percentage of your braking ability. And as the rear drums heat up, due to the thiness, they loose even moer of their braking ability. call me. ken

[pat in Santa Cruz]

I put a set of original stock cast drums on my sedan before I did the rears with new cast drums. I drove it for a year before I did the rears.. The brakes were better than with the thin steel ones that were there prior.

[allen]

Originally Posted by Special Coupe Frank

That is the way the Ford Model A system was designed, in terms of the geometry of the operating levers...

The rear brakes apply first, then the fronts.

This is opposite of how drum brakes have been set-up since about WW II (60% front / 40% rear).

As Kurt mentioned, this was the first Ford with 4-wheel brakes; previous Fords ( and most other cars / trucks ) only had brakes on the rear wheels and/or the driveshaft.

At that time, there was an unholy fear of having brakes on the front wheels, on the theory that if you locked-up the front wheels, that took away their steering ability... this was still a concern when the Model A was designed, and they designed the brakes to have the rears apply first, followed by the fronts.

You really can't change this much without modifying the brake operating levers up front. And most Model A-ers don't feel it necessary: well-maintained stock brakes are quite effective.

" 100 percent correct" this is why you use the stepper (wood stepper) to set the brakes up, if set right will brake as well or better than juice

[Jim Johnston]

I put cast iron drums on the front, and then two years later I did the rears - no problems whatsoever.

[CarlG]

Are there other things you have to change when going to cast drums, or are they just a bolt-on?

[hardtimes]

Originally Posted by robert shreveport

If you are going to change to cast iron drums can you change just the front and good results.

Robert,
I bought a set of front cast drums(slightly used)from a guy off the old fordbarn and did just what you suggest..on the front. After adjusting, the brakeing , in my opinion, was better.
More modern autos are designed to have more braking on the front (than model a design) because of a number of reasons including weight transfer during braking. Increased auto speeds, improved technology/materials, etc.. obviously impact braking design/use.
BTW..just bolt on improvement.

[Special Coupe Frank]

Originally Posted by CarlG

Are there other things you have to change when going to cast drums, or are they just a bolt-on?

Well, not exactly "bolt-on" in this respect: the old lug studs have to be cut-off and drilled-out ( or removed with a swage-cutter), to liberate the hubs from the old drums, then the new drums are fitted to the hubs, and the new lug-studs must be swaged-in.

Then the whole shootin' match is put on the brake-lathe, and the drums turned-true.


To swage the studs requires a 30-ton press minimum, and the proper swaging tools and backing supports... to try it any other way invites damage to the parts and possible injury to yourself / any helpers.

And DO NOT look at the studs and think, " Oh, there's a flat spot in the head to clear the hub: that will keep it from turning, I'll just leave the studs loose and the lug-nuts will draw everything together nice and tight."
It DON'T WORK !
(Previous owner of my coupe tried this on the LF... what a mess ! )


Aside from properly assembling the new drums to the hubs, swaging the new studs, and turning the drums true, all of which can be done by a good auto machine shop, this is a bolt-on job, no mods to the car.

[KCTA Chris]

I did the same but in reverse, I'm running worn stock steel drums up front and spent the money on new cast rears understanding there was more braking on the back.

Not that I want to be cheap about brakes, but to restore to factory working order has been costly and time consuming. I decided to get all the mechanical in factory new condition first. Front drums will happen when I'm ready to turn off my gravel test road and enter real driving.

I used "The Model A Medic" in Wichita for my new drums, hub truing and arching pads, was very happy with the quality and service.

[V4F]

i ran rocky mountains in the front for awhile & liked them . no have cast on the rear also . great brakes ...........

[darrylkmc]

If you are able to locate the late '31 Front 5 Spoke Cast Iron Drums (sometimes called Rocky Mountain)with enough meat left and good studs, all you have to do is make sure that they are round and true. The Drum and Hub are a one piece casting. 5 studs, one Drum/Hub assembly.

[dr.j]

who sells the best rear brake drums with studs and everything complete ready to turn and install?

[Vic in E-TN]

Dave:
I would contact Mel Gross in LA. He often posts for sale on the parts section of the Barn. Good product, reasonable prices and quick service.
Vic

[robert shreveport]

Thanks guys for the discussion, think I will do back first.

[BRENT in 10-uh-C]

Originally Posted by dr.j

who sells the best rear brake drums with studs and everything complete ready to turn and install?

I guess this solely depends on one's definition of "best". There are basically 3 manufacturers but basically 2 types available. There are the Made in USA units available that are Ductile and made to DOT specification ...and there is the one imported from China that are not Ductile. If it is the "best price" that someone is looking for, then we can likely guess where to get those. While one's wallet is the large factor that must make the decision, just think about the complaining that goes on around here regarding cheap off-shore repro parts being manufactured and sold by Model A parts vendors. To me, it seems when a Model A vendor steps up and offers a US manufactured top-quality product, we should if at all possible support them with our purchases. Otherwise if we don't, then our options are less when we need quality replacement parts for our cars. No need for a rebutal, ...just food for thought.

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