Brake shoe centering instructions
- Thread starter A31Woody
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I Just Rebuilt My Rear Brakes With An Assist ( More Like I Assisted Them) From Two Men In Our Model A Club. I Bought A Brake Centering Tool They Didn't Use The tool. They Backed Off Adjuster,Made Sure Where The Lining Were Setting, Put On Brake Drum Made Sure They Turned Freely On And Off Until It Was Right.
jdupay
Member
Besides backing off on the adjuster - I assume all the way off so it was providing not force, did they adjust anything? This brake centering thing has always been a question for me also.
RHD
Well-known member
Brake shoe centering is covered fully in my book "The Complete Model 'A' Ford Restoration Manual". 435 pages, all color. Over 1000 color pictures on every topic. The bigger and better second edition is now in print.The brake centering section is on page 132.
Sold by most leading Model 'A' Ford Parts suppliers or on eBay. I suggest Mikes Affordable.
Sold by most leading Model 'A' Ford Parts suppliers or on eBay. I suggest Mikes Affordable.
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Kurt in NJ
Well-known member
I use a Barrett Brake doktor to arc and center shoes on fixed anchor brakes --it has a tool toi measure the drum and set the machine
the parts places sell flathead teds roller pins with square heads---choose the flat that centers best
Some of the old model a books talk about bending the roller track---I don't
the parts places sell flathead teds roller pins with square heads---choose the flat that centers best
Some of the old model a books talk about bending the roller track---I don't
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Art Newland
Well-known member
Kurt, that's the ticket for sure! But impractical for us average Model A types.
Kurt in NJ
Well-known member
I bought my first one at Hershey, 10$,15 for new bearings, salvaged cord
For most of my machinery I have been able to buy for less than it would cost to get the job done---- I learned long ago that I could screw it up 3 times myself for less than I would pay someone else to screw it up
For most of my machinery I have been able to buy for less than it would cost to get the job done---- I learned long ago that I could screw it up 3 times myself for less than I would pay someone else to screw it up
Y-Blockhead
Well-known member
As does Les Andrews "Red Book". I don't think that is a good idea.
Either run a bead along the top of the roller tracks and restore so they are flat and the correct measurement or use FHT's adjustable square pins if the tracks are not too beat up. New tracks are another option.
That's quite the "machine" you have there Kurt.
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BRENT in 10-uh-C
Well-known member
Yeah, I also agree. When you try doing it, it is much more difficult than it sounds, and then it opens a whole new set of issues. I subscribe to fixing the parent issue and don't Band-Aid something with a McGuyver-type repair.
Actually, when you align new tracks to the Ford Print dimension, and then arc the shoes to the drums, you will find they are already centered. We made a fixture that helps us align them, but if you make the roller track surface 4.620" from the center of the housing plate. you are good to go.
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KR500
Senior Member
Brent, The guys using the various arcing machines, I believe are using the fixed clamp that does not center the shoe. The shoe should be fixture d so that the holes at each end of the shoe are equidistant from the center of the arcing band. Just arcing the shoe on a standard clamp does not take into consideration the centering of the ends of the shoes. Is your fixture one that locates off the shoe holes and centers them on the archer? The other clamp which is a fixed anchor style may be more adaptable to doing A shoes.
Keith True
Well-known member
I never quite understood the track bending thing either.The tracks have to rise up evenly,like an elevator.If you bend them,just the ends rise up.When that wedge pushes the shoe outward,it has to go straight out.With a bent track isn't the shoe going to rise up?That track isn't something that lends itself to bending either.Actually,I've found that after installing new tracks the shoes have been nearly perfectly centered.I put the brake dokter on,adjust the shoes to the drum size using the Barrett micrometer that comes in the kit,and find I need to trim off almost no material.
Al 29Tudor
Well-known member
We have been using the dimensions from Les Andrews:
Front brakes, page 1-37, 1.312 from shoulder of rivet to the track.
Rear brakes, page 1-41, 1.000 from shoulder of rivet to the track.
Weld up the tracks and mill them on the Bridgport.
Al Leach
Front brakes, page 1-37, 1.312 from shoulder of rivet to the track.
Rear brakes, page 1-41, 1.000 from shoulder of rivet to the track.
Weld up the tracks and mill them on the Bridgport.
Al Leach
BRENT in 10-uh-C
Well-known member
I think we are speaking of two different things. My arcing machine actually reshapes the lining to the contour diameter of the drum. My fixture is more to align the brake tracks to the housing plates when we rivet them on. At that point, if the tracks are in the correct location, and the roller pins are the correct dimension, then the shoes automatically align with the drum. FWIW, the proper Ford nomenclature for the A-2017 piece that everyone calls "tracks" is called Front Brake Shoe Centering Bracket. I don't believe that name was just by coincidence.
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Al, I don't have a drawing of the A-2227 Brake Spring Retracting Stud (a/k/a 'rivet') to look at to get the diameter dimensions, but I suspect there is an issue with that number that Les is giving. On the A-2017 print, it calls for the "rivet hole" to be punched from .258"-.263". That gives a .005" variance for the tracks to misaligned. It also calls for the Support Surfaces to be 1.496"-1.498" from the centerline of the punched hole.
What is written on the print is more to what needs to be the datum. It specifically shows the support surface of the Shoe Centering Bracket is to be 4.619"-4.624" from the centerline of the plate center hole. Even that dimension is specified to have no more than a .005" tolerance, but in big capitol letters it says "LOCATE ACCURATELY TO THIS DIMENSION. DO NOT GRIND." and it has arrows drawn specifically to the centerline of the center hole and the surface of the track.
We can use other points of reference that potentially have a great chance to be off collectively .010, .020, .030, -maybe even some .040 or .050 of an inch! My personal take on this verbiage means that Ford did not use some spindle mounted shoe arcing machine to locate the shoes, -nor did he prescribe to bend tracks or whatever. They knew that if they held to the tolerances of the prints, they would assemble and work properly. My point is it appears we often lose our baseline trying to come up with our own dimensions instead of using the actual Ford specified dimensions. And for what it's worth, Ford did not offer the A-2017 bracket for the Ford Agency mechanic to install themselves. The dimension was too critical for proper braking.
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Al 29Tudor
Well-known member
Brent,
Yes two separate issues.
I agree that using the centerline of the large hole as a baseline, once the "track bracket" has been installed reduces tolerance buildup of various parts.
This is the most accurate location for the tracks.
Now that we have the Ford dimension of 4.619-4.624 we will use this location.
Thanks,
Al
Yes two separate issues.
I agree that using the centerline of the large hole as a baseline, once the "track bracket" has been installed reduces tolerance buildup of various parts.
This is the most accurate location for the tracks.
Now that we have the Ford dimension of 4.619-4.624 we will use this location.
Thanks,
Al
1955cj5
Well-known member
As does Les Andrews "Red Book". I don't think that is a good idea.
Either run a bead along the top of the roller tracks and restore so they are flat and the correct measurement or use FHT's adjustable square pins if the tracks are not too beat up. New tracks are another option.
That's quite the "machine" you have there Kurt.
Who or what is FHT?
Thanks!
Google found them...
http://www.snydersantiqueauto.com/shoe-centering-pins
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Bob Bidonde
Well-known member
Flathead Ted's brake kit is the way to go. The brakes center every time regardless of wear. I have Ted's kit on my 190A, and yesterday I checked the front brake lining contacts with the drums. With about 500 miles of wear, contact is 100%! Wow! In all of the years I have been driving my Model A's, never have the brakes worked so well until the installation of Ted's kit.
redmodelt
Well-known member
Wouldn't you have to have the shoes expanded to the working position to get them centered using something like the brake doctor? The shoes are fixed at one end which is set by the adjusters so when they are pushed out the centering is change if they were done in the relaxed position. When adjusting the brakes you are really only moving the end at the adjusters, the other end stays relaxed till the rods are pulled and shoes are brought into contact with the drums.
BRENT in 10-uh-C
Well-known member
Are you suggesting that even when Ted's pins wear that the brake shoes will still center every time?
BRENT in 10-uh-C
Well-known member
You are exactly correct. That is why a measurement is (should be) taken of the diameter of the drum and the shoe lining is arced to the same parabolic shape.
Kevin in NJ
Well-known member
Another thing to keep in mind about the centering.
Because the one end is kept the same distance, when you crank out the adjuster you effectively move the center of the shoes towards the adjuster. So if you center the shoes and have to do a lot of adjustment after you put the drum on then you have moved the center some.
Something to keep in mind as you approach you brake set up.
Because the one end is kept the same distance, when you crank out the adjuster you effectively move the center of the shoes towards the adjuster. So if you center the shoes and have to do a lot of adjustment after you put the drum on then you have moved the center some.
Something to keep in mind as you approach you brake set up.