Brake centering tool

[ctlikon0712]

Also, if you have drums that are turned several times, to much may have to "ground" off and leave the shoes too thin as Marco say's. A thicker shoe material may be found and installed onto the shoe so that more may be ground to get the proper size.

 

[Marco Tahtaras]

Marco, Not sure I understand your point. If you center the shoes around the axle, and the drum braking surface is by design centered on the axle, how does it matter if the drum is oversized?

It's tough to describe all the variables with the geometry. In simple terms using a front brake as an example. Lets say you center the shoes at .040" smaller than the drum. What is the first thing you do after installing the drum? You go to the top of the backing plate and crank in the adjusting wedge until you get a "slight drag" on the brake. What you have done is expanded the TOPS of the shoes a bit over .020" while the lower end or "toe" of the shoes remain fixed on the tracks. You have now enlarged the circle UPWARD which raises the center of that circle. That means if you've bent the roller tracks, or better yet used custom roller pins to set the height or vertical center of the shoes you've just undone that work.

Now it IS possible to get close with a cheap centering tool as long as it holds it's setting. Start by installing the brake drum completely. Next, adjust the wedge until you have a very slight drag. Remove the drum and adjust the centering tool to the highest point on the shoes where drum contact occurred. Ideally that would be the heal of both shoes but more likely it will be the heel of JUST ONE.

 

[1931 flamingo]

It would be interesting to know how this was all done when assembled when new.

Paul in CT

 

[Marco Tahtaras]

It would be interesting to know how this was all done when assembled when new.

Paul in CT

They had all new, accurately made components. All they had to do is assemble them! As an example, the roller tracks were machined AFTER assembling to the brake housing (backing plate) so the positioning was right on.

 

[ctlikon0712]

Here, this is from a 40's Barrett manual I bought on fleabay. These first 4 pages are Ford mechanical brakes basic adjustments. I hope everyone enjoy's the read! lol

 

[ctlikon0712]

And these 12 pages are a trouble shooting guidelines.

 

[Hook]

I've read this thread a few times, and I think I "get" the concept. In Marco's most recent reply, you explained what most likely we'll find. How do you correct and center the shoes if in fact the heal of one is higher? Is the only way to sand the high spots with a tool I don't have? Do most people just have the shoes arched and get by without the centering? I have just removed all my brakes and backing plates and am getting the shoes religned and arched. I really appreciate all the insight from you more experienced Barn guys.

 

[ctlikon0712]

Hook, section E on page 3 of the 4 page post above adresses that problem.

 

[Dave N.]

Marco,
Your explanation really helped my understand the importance of the shoe arching. Thank you.

 

[Ed Northrop]

I was tinking of lining the inside of my brake drums with self stick sandpaper that comes in rolls and sanding the brakes to the same arch as the drums. Has any one tried this.

 

[SteveB31]

Marco,

Your one paragraph a few posts up SHOULD make it make sense for everyone. It is a very simple deal, once you understand it. Read his past post.