Disc brakes

[jeepguy1948]

Has anybody figured out how to do disc brakes (front and/or rear) whike staying with wire wheels (I realize that most any set up will require the re enforcing rings).

[jack backer]

Little known Model A trivia.. during development the hub of the wheel was used as the brake drum..’Cast Iron’ Charlie Sorenson, a production man, made the argument against this design seeing production.. his concern? The general public changing a tire and wheel and not adjusting the brake… it’s why the tire is easy to change with the wheel on the car.

[Charlie Stephens]

A friend of mine put disc brakes on his Model A (street rod). He soon regretted it due to brake dust all over the wire wheels. Disc brakes are great if you are driving through deep water (a stream running across the highway) or down a steep hill with a trailer. Otherwise I would put Lincoln brakes (first choice) on or the early Ford brakes (1939-48).

Charlie Stephens

[john in illinois]

I agree with charlie. Plus discs put a lot of strain on thr front axle.
I use lincoln front and Ford rear. Near 60/40 braking front to rear. No proportioning valve to fool with.

John

[Pete]

There is no dust if you get the right pads for the type of driving you do.
I have 4 wheel Wilwood discs on my 30 2 door street driver. No dust.
When I first put discs on, I had original 19 inch wire wheels. I had to modify the wheels slightly but they worked fine. I took the wheels off because of the too narrow tire footprint.

There is no more strain with discs on the front axle than any type of brake would apply to it under the same conditions.
No proportioning valve required with proper kit.

[jeepguy1948]

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I guess I need to point out that I did not ask if I should do it and I didn't ask if I shouldn't do it. I asked if anybody HAD done it (while staying with wire wheels (in my case '35 wire wheels)).

[Charlie Stephens]

Originally Posted by '28 RPU

I guess I need to point out that I did not ask if I should do it and I didn't ask if I shouldn't do it. I asked if anybody HAD done it (while staying with wire wheels (in my case '35 wire wheels)).

Please accept my sincere apology I was just trying to be helpful. I will try to remember not to bother you in the future with information I think might be valuable to you.

Charlie Stephens

[GeneBob]

28,
I have been in contact with Mike Hoskins from your earlier thread regarding disc brakes on the Model A. He is waiting on parts but I am very interested in pursuing this once he has the parts to put a kit together. We'll see who does this first!

[JOHNCL]

I am wondering how to have disk brakes on the front axle while using 5-on-5 1/2 bolt circle wheels. I need how to do it advice.

[updraught]

https://www.fordbarn.com/forum/showp...0&postcount=46

[nkaminar]

Audi had disk brakes in the 80's which were inside out. The calipers were mounted on the inside diameter of the disks while the disks were held at the outer diameter. I am wondering if something like that could be used on the Model A. The calipers could be hidden inside what would look like a drum brake. The car would appear to have the stock brakes but have disk brakes inside the drums. The wheels would be mounted as usual.

An engineering challenge for sure.

[CarlG]

Originally Posted by nkaminar

Audi had disk brakes in the 80's which were inside out. The calipers were mounted on the inside diameter of the disks while the disks were held at the outer diameter. I am wondering if something like that could be used on the Model A. The calipers could be hidden inside what would look like a drum brake. The car would appear to have the stock brakes but have disk brakes inside the drums. The wheels would be mounted as usual.

An engineering challenge for sure.

When, and if that happens, I may be up for that.

[Synchro909]

IMO, if the discs were mounted inside the drum, ventilation would be a problem. They would get awful hot. To ventilate them well enough would make them visible, defeating the whole purpose of putting them in the drum.

[Jim Brierley]

I have a business card from Mike Hoskins, I know nothing about him. [email protected]
it says Model A disc brakes.

[nkaminar]

Synchro, I suppose the backing plates could be mostly open with maybe have a scoop to encourage air to flow into the brakes. Anyway, it is just fun to think about it and probably nothing will happen.

[GeneBob]

From my conversation with Mike, he is waiting on parts but his kit includes discs that allow you to use Model A and other 5 on 5.5 inch wheels. He is working with a local supplier to provide custom calipers that place the bleed screw in to proper location and use readily available brake pads (maybe the metric GM?) His kit puts discs on the rear as well as the front to try to avoid the proportioning valve challenge of a disc/drum system. I don't know if he is building in any difference in piston size to bias to the front. He has built a prototype of this this on his own car. His plan is to keep it simple.
I am surprised that he has not posted to this thread but he is pretty busy.

[jack backer]

The proportion valve is used to bias the braking pressure to the front, stock model a’s are biased to the rear.

[40 Deluxe]

If you're keeping the 19" or 21" wheels the stock mechanical brakes are capable of sliding (locking up) the tires. If you spend a bajillion dollars on disc brakes, they too will lock up the tires. So where are the benefits? Disc brakes have better fade resistance, true, but do you really drive your stock (or nearly stock) Model A that hard??

[GeneBob]

I think you would want either a proportioning valve or bigger caliper pistons or bigger discs in the front but hey, anyone can bias to the front or rear if they choose.
The advantage that I see is for people who frequently drive the car and are driving at speeds beyond the stock Model A. Nothing against a stocker that is driven within its limits but some of us are a little crazy and are always pushing for more. More speed, better tires, more brake capability with much less fade. I have definitely crossed the line into "hot rodding" the car. For those who like the stock Model A, changing to disc brakes is not even a consideration. I often wonder if I should have stayed on the other side of the line.

[jack backer]

I left the purist reservation too.. 40 deluxe is on to a key element of any braking system, traction. Skidding is not maximum braking, it’s a loss of control. I run 16” ford wires and modern radials for that reason..stopping, not sliding.

[Pete]

If you are fine tuning your car for racing, Wilwood has a pedal assembly that can be installed either swing or floor, has dual master cylinders and is bias adjustable.
No need for propotioning valves, different size wheel cylinders etc etc...
It is even modifiedable to be adjustable while racing if need be.(Like rally racing where part of the course is on dirt.)
They also have a mechanical parking brake assembly.

[nomadpsd]

They have been doing disc brakes inside Buick style drums for many years.

[jeepguy1948]

Same with be Jack. I would like to do this because I like the pedal feel of all discs and also simply Cuz I Want to. Very few things are impossible, especially if you have more dollars than sense. I keep turning over rocks in hopes of finding somebody who has done it, that's how I found Mike Hoskins. Mike has what looks to be a great product but he is really hung up because his rotors are in "Supply Chain Hell".

[nomadpsd]

I researched doing disc brakes with stock wheels a few years ago. One of the problems I found, was the shape of the wheel. The wheel contacts the drum at three points. A disc brake rotor would only use two of these points. Also, because of the way the wheel is dished, the rotor would have to have a large offset. I ended up going with a complete Randy Gross cast iron drum setup.
[IMG][/IMG]

[jeepguy1948]

Nomad, that's good information. I have a Randy Gross steering box but don't know anything about what they offer for brakes? Thanks, Don

[jeepguy1948]

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So what I would need would be a narrowed front axle to allow room for the disc brakes plus the support rings for the wire wheels.

[GeneBob]

Originally Posted by '28 RPU

So what I would need would be a narrowed front axle to allow room for the disc brakes plus the support rings for the wire wheels.

28,
Not necessarily. If the discs and calipers are offset inboard, the wheel stays where it is. I don't know if this is the case, but it is a possibility.

[Kelly.s]

Originally Posted by jeepguy1948

Has anybody figured out how to do disc brakes (front and/or rear) whike staying with wire wheels (I realize that most any set up will require the re enforcing rings).

So what did you decide. I’m starting a new project that went thru a forest fire, everything is gone.

Kelly

[nkaminar]

I had disk brakes on the back of my Model T. The front, of course, had no brakes. Now, the Model T is much lighter than a Model A, but I used to ride the brakes down steep grades with no ill effects. A stock Model T would have to go into low band and travel down the same grade at 5 mph. So my take on disk brakes is they they are fade resistant and would be handy coming down Pikes Peak.