Brake Parts / Ford Dimensions

[Rob Doe]

Has anyone got the correct specs for the brake roller pins and the rollers? A curious mind wants to put them in his notes for his grandsons. Hopefully, someone has the Ford drawing or a reliable source???

Roller pin length
Roller pin shank diameter
Roller pin head diameter
Roller pin head thickness

Roller diameter
Roller hole diameter

Thanks

 

[Joe K]

This sounds like a job for the ORIGINAL DRAWINGS.

https://www.thehenryford.org/collec...-resources/popular-topics/ford-parts-drawings

And a similar request over at the T Board

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[SIZE=-1]By Fred Miller, Sequim WA on Friday, July 19, 2013 - 09:11 pm:[/SIZE]

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Tod, I have purchased many original plans and other parts documents from Ford Benson Research for my TT's. FBR has quite a few plans that they have to search for using the Part number. I have not been able to get all that I have asked for but many of what I did get were very informative and sometimes were not the same as the modern understanding of certain parts. This can be just the beginning of your journey.

Start here at their Site.
http://www.thehenryford.org/research/partsDrawings.aspx

An index for the Model A exists at the first link. The respective parts numbers (still in "modified" use by the modern parts dealers) would be a help.

IIRC, there is a charge for "duplications" which is not large, but there is inherent some question about "are you paying for what you want." And should you choose to "replicate" for profit there is the copyright matter and attribution agreements. The Index may help.

Some here who are into reproducing likely can tell you more of the pitfalls. And may share (generously) what drawings they have "offline" (ahem.) But your parts of interest are so severely "common" that even that is unlikely?

I commend your interest for "originality." So much of what is in the marketplace comes with decidedly "uncertain" pedigree. The recent discussion of "clustershaft roller bearings" comes to mind.

It is better than it used to be.

Joe K

 

[BRENT in 10-uh-C]

I have the prints but I am not where I can view them at the moment. By memory, I can tell you the pin is 7/16" in diameter (0.4375") and the hole in the Roller is 0.4380" and the OD is 1.250". I will get you the print numbers if you like later today or this evening.

 

[Rob Doe]

I have the prints but I am not where I can view them at the moment. By memory, I can tell you the pin is 7/16" in diameter (0.4375") and the hole in the Roller is 0.4380" and the OD is 1.250". I will get you the print numbers if you like later today or this evening.

Thank you, Brent. I'll appreciate getting them.

 

[njw5]

I found this link to Roller Pin dimensions on the web that you can view the pin drawing. Its revision is '32 but I can't tell what changed between the model A and the Model B roller pin. (if any)

.thehenryford.org collections explore artifact 483183?AssetId=THF407663

I see references on some supplier websites that Model B 32-34 and Model A 28-31 all use the same roller pin.

From what I can tell many of the newer pins are undersized for pin diameter and in my opinion puts the rollers in a bind (in assembly) so they can't spin freely as maybe the original design intended. But I've only been at this for a year now...

Can anyone confirm this drawing reference would be the same dimensions for Model A's?

I would think that if the roller's ID is 0.438, the holes in the brake shoe should be the same? Which makes sense for the diameter of the roller pin in the drawing being max 0.4365 diam.

 

[Synchro909]

A timely thread! I am about to make 8 roller pins for 2 of my cars that I am fitting 1934 front brakes for obvious reasons. I don't like the pins from the vendors - the heads ar too rounded and too short so that they do not use the full width of the track. That increases the wear rate, making a re-do needed sooner. In addition, I have 6 new rollers (more coming) that are too thick for the standard pins. I can't get them fitted to the brake shoe and get the split pin in. I will make them from a 16 mm (5/8") dia piece of 10/45 steel, then heat treat it to toughen them up. The heads will be shaped on the lathe, not the rounded shape the vendor ones end up with when they are made by pressing the end of the pin and forming the head rather like a rivet and they will be wide enough that the head rides on the whole width of the track. That should be way more durable.
Opinions?

 

[njw5]

What are your 2 cars you are fitting '34 brakes to? (I'm new - so there are no obvious reasons.)

I am also of the opinion that many of the replacement roller pin heads don't have enough surface area to properly ride on the roller track. Too much radius/chamfer on both sides of the pin head and not enough 'flat'. I've yet to figure out how much of the head is riding on the flat track to know if it is a problem or not.

Cotterpin hole & stackup - If rollers are 0.25" thick each and the meat of the shoe the pin goes thru is 0.25" thick how far from the head of the pin do you plan to put your cotter pin hole's edge? (i'm sure shoe thickness varies more across parts than the roller thickness does) I would think some play between all the components is prudent, just don't know how much - although the drawing does have a min max dimension to the center of the cotter pin hole from the head.

Do you have a target rockwell for your surface hardening?

But I am very curious - how to avoid rust? I believe current pins are plated for that avoidance.

 

[Tom Smith]

I found over the years Brattons carried the most accuretly dimeonsioned Roller and the head on the roller pin was correct. I stocked up when they went out of business.

 

[Synchro909]

What are your 2 cars you are fitting '34 brakes to? (I'm new - so there are no obvious reasons.)

I am also of the opinion that many of the replacement roller pin heads don't have enough surface area to properly ride on the roller track. Too much radius/chamfer on both sides of the pin head and not enough 'flat'. I've yet to figure out how much of the head is riding on the flat track to know if it is a problem or not.

Cotterpin hole & stackup - If rollers are 0.25" thick each and the meat of the shoe the pin goes thru is 0.25" thick how far from the head of the pin do you plan to put your cotter pin hole's edge? (i'm sure shoe thickness varies more across parts than the roller thickness does) I would think some play between all the components is prudent, just don't know how much - although the drawing does have a min max dimension to the center of the cotter pin hole from the head.

Do you have a target rockwell for your surface hardening?

But I am very curious - how to avoid rust? I believe current pins are plated for that avoidance.

I already have them on my 1929 Phaeton and they will also go on my 1928 Tudor and a 1928 farm Ute I made from pieces. I drive the wheels off them all. The 32-34 brakes are 12 inches diameter, while the Model A ones are 11 inches. Result: better braking. From 1935, the shoes were wider so I kept it simple and used the later ones with the same width shoes.
I clean up the inside of the drums and have the shoes relined (they arrive without linings because NO asbestos is allowed into the country). The linings are fitted to the drums and all moving components are repaired/replaced.
Pedal pressure is still high but I know I have plenty of "stop" left when the Model A brakes would have faded to useless.
Hardness on the pin? The ones I have seen are not very hard, just a little harder than untreated steel. I figure twice through the heat and cool process with 1045 steel will be plenty.
IMO, we are given these cheap to produce brake components just to boost the profits of the vendor and to hell with the safety of the buyer. I'd prefer to stay alive so I say "to hell with the vendor's profit".