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jclary
10-02-2009, 02:45 PM
Back in the early 1980’s, when I was making my sales calls in mid-South Carolina, I would stop by Mr. Herbert Boykin’s garage in Lugoff every opportunity time would permit. Herbert was one of those old grizzled southern guys who no matter how boisterous or grumpy…the intimidation factor was always betrayed by the gleam in his eye. It was not uncommon for him and his employees to have something like a gas burner with a pot of boiled peanuts or chicken gumbo steaming for lunch as they worked.

On this particular occasion he was in the middle of a brake job on one of his customer’s Studebakers. We exchanged pleasantries as Herbert worked away hardly glancing up to acknowledge my presence. He was dressed in his usual coveralls, sitting in on the dusty stained concrete floor with a brake drum between his legs. Eager to learn something (without admitting I had something to learn) I leaned down to get a closer look at Herbert’s work. Suddenly I was startled as Herbert’s hand with a brake shoe rapidly whooshed by my face as he raised it and slammed it onto the flat surface of a big blacksmith type anvil on the floor next to him. Then he placed the brake shoe back in the brake drum he had between his legs. I watched as he slid a piece of paper between the shoe and the drum’s brake surface. Again, he whacked the shoe on the anvil, only this time instead of hitting end of the shoe on the flat surface…he struck the shoe in the middle of the arch onto the horn of the anvil. Placing it back in the drum and using both hands he pressed on both ends of the shoe, then attempted to slide the thin piece of paper between the shoe and drum in the middle again…but it wouldn’t go…”PERFECT!”, he exclaimed! I asked what he was doing and he explained he had turned the drums and that if he didn’t match the curve of the brake shoes, they wouldn’t have full contact and would result in poor braking performance. Of course, by this time the fact that I was about to learn something was obvious. I remarked that since the shoe had the welded steel arched “web” on the inside of the back of the shoe…I didn’t see how it was possible to cause it to bend. Herbert explained that we are only talking about extreme fractions of measurements and proceeded to prove to me how it was done on the remaining three wheels. By either “Spreading” the shoe …striking it hard on the end…or “Collapsing” the shoe striking it in the middle…it is possible to match the curve of the brake drum. When you place the shoe in the drum to check…if it rocks from end to end…it needs to be spread out…if it does not “rock” but you can see “a no contact” space in the middle…it needs to be collapsed in. It’s that simple. Herbert explained that this was what made his dirt track racers “out brake” the competition, and allowed his “bootlegger” customers make that quick turn that would enable them to “get away!”

A few weeks before my oldest Brother died of cancer…I took him for a ride in my ‘55 truck. He commented that he had never seen a Studebaker with brakes as good as mine. He gave me a bit of a puzzled look as I replied, “You can thank ol’ Herbert for that.”
:)

John Clary
Greer, SC
http://i518.photobucket.com/albums/u346/jconln/HPIM0372-2.jpg
Life... is what happens as you are making plans.
SDC member since 1975

DEEPNHOCK
10-02-2009, 03:14 PM
The term used to bend a shoe to correct it's arc is 'coining'.
They still do it in the remanufacture of the big HD brake shoes.

Arcing shoes to fit a cut drum has become a lost art, as the DOT mandatory spec of x.060" max is pretty strict.
Used to be there was more meat in a drum and when the shoe (with new lining) would not match the arc, they would put overside linings on and 'arc' them to match the drum.
Finding oversize linings, while not impossible, is pretty hard nowadays.

You still see old arcing grinders in the corners of some old shops.
Interesting post....
Jeff[8D]

klifton1
10-02-2009, 03:25 PM
I just had this done on the 46 Fxxd brakes on my V8 powered 29 roadster pickup. They work perfect. It was also done on my Speedster. It has drums all the way around.
Klif

55 Speedster
63 Avanti R2
63 Lark R2

jackb
10-02-2009, 05:30 PM
Ok... so I think I'm reading this correctly. "Arching" or "coining" a pair of shoes to the drum is re-configuring the metal part of the shoe, not simply turning down the brake shoe material to fit the drum contour ?????

41 Frank
10-02-2009, 05:49 PM
I arced brake shoes for three decades as a mechanic, we did it, in house, for vans,trucks and busses and it consisted of grinding the heel and toe of the shoe material until it fit the drum diameter with a few thousands clearance on the ends.This has always been the acceptable way of doing it in the industry.

jclary
10-02-2009, 06:27 PM
quote:Originally posted by jackb

Ok... so I think I'm reading this correctly. "Arching" or "coining" a pair of shoes to the drum is re-configuring the metal part of the shoe, not simply turning down the brake shoe material to fit the drum contour ?????


As you can see by the comments, there is more than one way to "skin a cat" so to speak. The method Herbert showed me is a kind of "back yard" method by old school mechanical masters that learned how to make things work with little resources available.Like all of the "tricks of the trade" there is some skill and art involved and those without the mechanical aptitude or ability to sense the nuances, should leave it to the pros. I suspect that when you get to the larger shoes used on big trucks, removing brake shoe material is a more practical option.
You have to realize that we are talking about minuscule changes...large changes would probably indicate a serious problem with either drums cut too much to be safe to use or a poor quality shoe.

John Clary
Greer, SC
http://i518.photobucket.com/albums/u346/jconln/HPIM0372-2.jpg
Life... is what happens as you are making plans.
SDC member since 1975

buddymander
10-02-2009, 06:58 PM
I've cut the rib with a die grinder then clamped the shoe in the drum and tack welded it.

gordr
10-02-2009, 09:21 PM
Thanks for posting this, John. A real fine piece of writing, too.

I've used a brake shoe grinder to re-arc shoes, but this is a new one on me. And it makes perfect sense. I'll try it the next time I do a set of drum brakes.

Gord Richmond, within Weasel range of the Alberta Badlands

rockinhawk
10-02-2009, 09:35 PM
I was taught to do it the same way as Mr. Boykin. The my teacher said "But they'll wear in after you drive it awhile anyway". So I usually don't bother unless they are really bad.
I met mr. Boykin in the early 80's. My wife and I were driving US1 from south GA. to Baltimore that summer,when she Exclaimed "There's a Studebaker on top of that building!" I really don't remember if it was actually on the building or up on a pole, but it was elevated. We stopped and had a nice visit with Mr. Boykin. Years later I bought a Studebaker with a decal on it with his name as the selling dealer. I thought that was cool. NT


Neil Thornton
Hazlehurst, GA
'57 Silver Hawk
'56 Sky Hawk
'51 2R16 dump truck
Many others.
http://i81.photobucket.com/albums/j209/mbstude/avatar2.jpg

BRUCESTUDE
10-02-2009, 11:36 PM
About 20 years ago the mechanic we had here at the Yakima Fire dept. arched some Stude brake shoes for me; he took a big hammer and tapped the center to "spread" it ever so slightly. He was a Packard shop foreman before becoming the FD mechanic. I since have not tried this, as I am always afraid it may affect the adhesive bond..?

buddymander
10-03-2009, 01:04 AM
Re-arcing by grinding severely shortens the life of the shoe. Any shoe that will bend by rapping it against something is also flexible enough to distort that same amount when the brakes are applied, bringing the shoes into full contact with the drum. Light braking will wear out the shoe in the center, just like arcing. By cutting and welding the heavier ribbed shoes, full contact is reached at shorter pedal travel, and shoe life is doubled.

maxpower1954
10-03-2009, 03:06 AM
Stan Gundry in his excellent Avanti book "What the shop manual doesn't tell you" describes adjusting the brake shoes by wacking them with a rubber mallet on a hard surface - it worked perfectly on my rear shoes to match the drum on my R-2 GT. I'm a believer! Russ Farris

buddymander
10-03-2009, 09:31 PM
If the shoe fits the drum perfectly, then the top and bottom of the shoe will be applied with more pressure, since the shoe is applied uniformly by pushing the ends down thereby bending the middle and applying equal pressure to the center. So I would leave 1/16" or so for bend on the ends.

maxpower1954
10-04-2009, 01:47 AM
Didn't think of that buddymander, good you brought that up! Russ Farris