I have an Ammco "Safe-Arc" shoe grinder with the No. 4140 fixed anchor Brake Shoe Grinding Clamp. Problem is I don't have the guide to tell me which guide plates to use. It's a more hi-tech version, made for Bendix fixed anchors systems.
I, too, learned about arcing shoes in the automotive ciriculum in college. As I remember, it really counts for something on the older, non self energizing brake systems, like '39-'48 Ford and '36-'50 Chevy.
Even though this is an old post it is an example of "STUPID" over regulation,common sense would dictate that if a drum were perfectly round and the shoes arced to said drum the contact area would almost be 100%,if contact area were only 80% which car would stop better and thus be safer? And the machines that make for more safety are banned? Go figure. also most drums and rotors sold over the counter are made in China,I'm sure they are perfectly true
I've NEVER found a drum out of the box that was "round". They all take at least .020 to get them true. Likewise I was taught to re-arc the shoes to the new drum diameter after the drum is turned. I'm trying to talk the owner of a recently closed auto parts store into selling me his drum lathe and re-arcing machine that has been unused since the federal mandate that they could no longer be used because of the asbestos contamination. I'd like to offer a service to the local hot rod and race crowd. Frank
I used to do brake jobs years ago with my dad, drums cut down and shoes arced, that's the right way............. I wish you lived closer............. Anybody in Maryland have this equipment, I need you when I do brakes on my 60 Vette,,,,,,,,,, PM me............... Thanks Jack
Funny, I was at my friends shop yesterday and we ere talking about the old brake shoe arcing machines. He said he used to have one but the E.P.A. doesn't allow it in California, so he had to stop doing it.
Contrary tp popular belief, after arc grinding, brake shoes are NOT supposed to contact the drum 100%. With Bendix style, the shoe is supposed to have .008" - .012" gap at each shoe end and rock slightly in the drum. With the old Ford Lockheed style, the gap is supposed to be more. I think about .014+". Check a technical brake manual. Mine was from Wagner brake products. I have a Bear Brake drum lathe and an AMMCO grinder. I'm looking for the small diameter arbor shaft for my lathe so I can do old Ford rear drums. My current 1" arbor won't go through the axle shaft hole in the hub.
Back in the day when every gas station and small garage was doing brakes relining and newer bonded shoes.This is what was done and worked well is chamfer the ends so they don,t hit top and bottom.This will make drum go on better and will let middle of shoes hit middle of drum.
The machines were banned because most of them didn't have any setup on them to catch the ASBESTOS dust (you have heard of asbestosis ?) and the dust ended up being blown around the whole shop area to float in the air for a while and end up on your clothes to be carried home to your family at the end of the day. A lot of us old brake mechanics, and I am one of those, had a real bad habit of blowing out every drum and brake shoes on the car with the air hose when we pulled the drums off. Again brake dust all over the shop, floating in the air, getting on your clothes and being hauled home to your house where it got in contact with your wife and kids. I wouldn't even consider running one of these machines unless it had a very good vacuum system hooked to it that had one hell of a filter setup on it's exhaust air. Brakes that are a bit mushy are a lot less of a worry than bad lungs are.
Got an old Ammco grinder when my kid's work closed up. Got it running, still need to learn how to work it. I picked up the sandpaper sleeves from goodtool-online.com/, part AS-7, $3.09 each currently.
i don't own a shoe grinder but here is what i did on my friends 30 Chrysler, after many trys at getting the shoes to contact the drums over most of the surface i had the shoes relined and started fresh, i added a little to the drum diameter dimension i gave to the shoe reliner so i would have a little to grind when i got them back, i took each drum as they were all a little different and started grinding the shoes on my belt grinder to get them close the drum, then i layed a piece of sand paper inside the drum and finished fitting them by hand, the sand paper didnt move it just stayed there as i rubbed the shoe back and forth, the extra thickness added by the paper gave the shoes a radius just slightly smaller then the drum allowing the shoes to contact at their centers more then at the ends, the car now has great brakes, every vehicle i own with drum brakes will get this process, super simple, if you don't have a belt grinder you can clamp a belt sander upside down in a vice and use that, try and keep the lining square with the shoe.
If one looks hard enough machines like yours can be found for sale for sale. Never done it myself, I have seen shoes with hard lining re-arced using a lathe.
in the 60-70s in des moines iowa ,there was a brake shop/manufacturer that did it all/ called "ackerman auto parts " they had about any new or antique brake related part you wanted ,closed in the early 80s or sold out BUT you know today i dont believe any of them shop guys are alive /a couple died of cancer / skin/lung related problems ! that i know of ! i always thought it would of been a neat place to work ,little did i know of the asbsbtos /related air born problems i could of got ? amen !
It is not just the asbestos they are worried about. New shoes no longer have asbestos but any dust is still bad for you. OSHA and the AQMD are all over it in a commercial environment. It is still legal if the equipment has the correct system ($$$) to contain the dust. Charlie Stephens
Go on eBay and purchase the user manual for this. The pic shows the model with the attachment that simulates the anchor pin. Did you get the metal tabs that are marked with drum diameters?
"I have decided there is a "tawain ruler" and its different than ours..." Yeah...I like having little 6" rulers all over the place so I can grab one any time I need a number. Found 2 different Chinese ones at a garage sale ("Hey, how could they screw up these?") and, on the way home, held them up side by side. There was a clearly visible difference between the lengths of an inch...took the easy way out and tossed both. Rule for measuring: The tool has to say "Browne and Sharp", "Starrett", or at least "General" (old USA General ONLY).
I think that a shoe grinder is a**** stuff offered for sale here on HAMB cl***ifieds and EBay now, and also the subject of a thread that contains some rather heated discussion of which I was a party I did this sort of work in a parts store back in the 50's and have asbestosis now from that and other sources. Luckily not to the mesothelioma phase you see on TV ads foir the ambulance chasers. But if I had room to keep one of these machines I prolly would still like to have one and put it on a bench with wheels to roll it out side to use with a dust mask. But since I only have one car with drum brakes I get by chamfering the ends of the shoes, and while being careful to not overheat things, do a lot of braking to seat in the shoes, along with ferquent adjustments till things seat in.
First step before you even think about using the damned thing is to figure out how to hook one hell of a vacuum and filtration system to it. That will probably be a high volume shop vac with a serious filter hooked to the exhaust side preferably exiting outside the garage and not even close to the house. The newer brakes may not have asbestos like the old ones did but the dust still gets in and on everything if you don't catch it. That is not only in your lungs and on your clothes and in your hair but in that new short block you have sitting on the engine stand 20 ft away and on the body parts you are prepping for pant on the other side of the shop.
Back in the 60s I did brake jobs for Sears. All their shop shoes were arked on site. Brake drums should be stored flat not on edge over time they will get out of round. Shoes are not arked for 100% contact but to a smaller circle than the drum. Shoes will flex when applied in a hard stop if arked for 100% contact they will flex and raise in the middle and not be full contact.
The Jalopy Journal
