arching shoes

[1930artdeco]

Hi All,

I just received some new shoes for Missy. However, I put the shoes in there drums and they almost all rocked a bit-I expected that. So I used my feeler gauge to determine what needs to be ground off. Fortunately, not much needs to be ground off. They measured anywhere from .006 to .020. I figured anything under .010 I would just let wear in naturally. Is this a good route or should I just arch them all regardless of the gap?

My question is that I have the machine to arch the shoes but the shoes are bonded on. Will standard sleeves work. They are the red oxide type and not a grey type like wet sanding paper.

Mike

[kenparker]

idoitto.

[kenparker]

sorry guys. the above post was an accident. ken

[BILL WILLIAMSON]

Artdeco,
We always ground the shoes .010" UNDER the drum size, to help them from squeeling/squeeking during the seating in. Ground that way, the shoe should just barely rock when you hold it in the drum. Jerry, at Fresno Brake taught me that "trick"
Bill W.

[jm29henry]

The parts suppliers make a centering tool I don't know if this will help just a thought

[marcshall]

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my back brakes are squeeling a lot especially when cold , i have new cast drums i will file them to make them just barely rock thanks bill williamsom

[700rpm]

There's an excellent article on this in the current "Restorer" by Lynn Sondenaa, including how to make a centering tool.

[Duffy1]

So what happens if you do not arch or center the shoes ? Will they wear in at some point in time ? The fellow that rebuilt my brakes did neither . When I questioned him on this he said " do not worry about it . The shoes will wear in to fit the drum "

[Kurt in NJ]

Originally Posted by Duffy1

So what happens if you do not arch or center the shoes ? Will they wear in at some point in time ? The fellow that rebuilt my brakes did neither . When I questioned him on this he said " do not worry about it . The shoes will wear in to fit the drum "

You end up with "bad brakes" and start thinking you need hydraulic---but a bad shoe fit makes for bad brakes with any system, when the lining only contacts a small area that spot gets very hot and you get quick fade--you could drive some, then sand or file just the small contact patch to speed up the "wearing in" process (like scraping in a bearing, keep removing the high spots until the contact area is most of the surface)

Don't worry about it, it's just an old car, it won't matter, the brakes aren't supposto work good ----common excuses

On a car that only gets driven a little it could take years for them to wear in, the old Mercedes drum brakes I send the drum diameter with the shoes and they come back fitting very close ( http://www.allfrictions.com/contactus.html ) , with the variation you have what are the drum diameters, perhaps that .020 shoe fit is really a too large drum diameter


The best way for cars with fixed anchor shoes is a Barrett Brake Doktor --it arches and centers the shoes on the car to the drum diameter --this is a 1930 Chrysler I fixed, even with everything good these hydraulic brakes don't work as good as A mechanicals---I wouldn't want it behind me when I stopped the A quick

[just plain bill]

You ARC brake shoes you don't ARCH them !!

[Marco Tahtaras]

Originally Posted by 700rpm

There's an excellent article on this in the current "Restorer" by Lynn Sondenaa, including how to make a centering tool.

Ok, you prompted me to finally remove the wrapper from my magazine. There are either some common oversights by the author or I'm missing something.

The author states "I attached a button indicator to the fixture to measure the the circumference in thousandths of an inch". What he is doing is simply measuring variations in the radius but not the actual radius which is critical. For example, if the drums measure 11.040" then the point of reference for centering the shoes must be a radius of 5.520" and the gauge must be set as such.

I see more issues with the setup but suspect the odds are that the result will still be better than most folks achieve.

[tbirdtbird]

I rub chalk on my linings then spin the wheels with the adjusters only adjusted for slight contact. I slip the drums off and see where the chalk is gone. Then I gently grind on that area with a 4" right angle grinder with an 80 grit disc. Repeat.

It is not perfect but it gets me pretty close. Brakes work really well

That woven lining holds up well, I just had the rear drums off last spring to install the Mitchell and there was barely any wear after 6000 miles

[Patrick L.]

When the grinder disappeared about 50 yrs ago I started to line the drum with sand paper and just sand the shoe to fit. It comes out undersize by the thickness of the paper and all you have to do is grind the relief on the ends.

[mack4759]

Originally Posted by Patrick L.

When the grinder disappeared about 50 yrs ago I started to line the drum with sand paper and just sand the shoe to fit. It comes out undersize by the thickness of the paper and all you have to do is grind the relief on the ends.

Patrick, what kind of sand paper do you use? Does it have an adhesive on the backside? Or how do you keep the paper in place?

Thanks

[Joe K]

I used regular 100 grit paper held with spray adhesive sold to picture framers. It's a light adhesive which is easily removed from the drum using acetone.

I see now that the orange place has small "sheets" of sand paper in various grits already sticky and a peel off back used with palm sanders. These might work well too.

And I used a mill-bastard file to taper the ends of the shoe back a bit, perhaps an inch on each end or a little more on the "trailing" edge of the show. It only took about 4 or five swipes of the file to accomplish this.

Joe K

[nick c]

The sanding paper is used on a hand held file for removing auto body filler. It is 2 3/4" X 17" long, some have glue on one side and some dont. You dont have to buy a whole pack of it, they also sell by the sheet, 80 grit will probably work.
If you had a drum that was turned to the max and the new shoes are not even close to fit. You can lay the shoe on an anvil and strike the web of the shoe and stretch it to fit the drum. I know this is shocking behavior, I've never done it to a model A, just on big trucks and equipment trailers.
carry on, nick c

[redmodelt]

You could also take the lining off and use brake shoe shims under the lining. Right or wrong I have been using a disk sander to fit/arc the shoes to the drums before I install.

[tbirdtbird]

"If you had a drum that was turned to the max and the new shoes are not even close to fit"

the suppliers have oversized lining for this purpose