Arcing Brake Shoes To The Drum

[Bingster]

I've read where it's best to have the brake shoes grounf to conform to the curvature of the brake drum.  Where does one have this done?  Any brake shop?  Is this still done on modern cars?  I guess when they leave the factory, but on a new brake job, do they still do this?  Thanks.

[Don Coatney]

Do a forum search and you will find a lot of information on this subject.

[desoto1939]

You will need to find an old brake shop that would still have the Ammco arcsafe brake grinding tool. When the repair shop would also reline the old rivited brake shoes then they would put them on the arcing machine to get the shoe to be perfect and to remove any high spots onthe brake lining and also to get them to match the arc of the drum. If the drum had been turned or cut to the max they would also shim the linings to also get a better fit.

With the advent of disk brakes this is no longer being done. Even though there are still using drum brakes the linings are bonded and the mechanics no longer to the arcing and grinding.

So also when the old shoes were used the linings were asbestos and this was a dangerous process of breathing in the dust. You still might find an old shop but they might not want to do this is you have old lining becasue of the asbestos and the dust.

There is someone inthe club that just purchased one of the safe arc machines. You might contact them to see if they would arc your shoes.

So basically most people try to get the shoes as close as possible and then let them wear into the drum arc. I have been seeing these safe arc grinders go for $700-800. That is a lot of money to have in a tool inwhich you might only arc one set of shoes. ANd even if you had the machine and charged to do the job how much could you charge and would there be enought work to offset the cost of the machione and the grinding drum sandpaper.

Rich Hartung

Desoto1939@aol.com

[TodFitch]

At my local hardware store I found a roll of sticky back sand paper. For each drum, I cut a strip of sand paper long enough to go around the full inside of the drum and stuck it in. Next I used a sharpie to mark some cross hatches on the shoes and then put them in the drum and rubbed them back and forth until the cross hatches were gone. That only took a minute or two a piece. I did each wheel separately so the shoes were lapped/arced to the drum they were being used with.

 

At this point I knew that the shoes were arced to the radius of the drum minus the thickness of the sand paper. The paper I got was a little thicker than I wanted but nonetheless the result was a lot closer than I started out with and it got the shoes close enough to allow me to use my Ammco shoe aligning tool.

 

Total cost was a couple of bucks for the roll of sand paper and I only used a little bit off the roll.

 

Since then I've acquired an Ammco shoe grinding tool but I haven't used it yet as the above has been good enough to get me the best brakes I've had in years on that car.

[Bingster]

Thanks guys!