Im in the middle of doing the brakes on my 49, and I was wondering what requires drums to be turned? I have 4 front drums for it, and none are scored. Just slight surface rust from sitting. Could I clean them up with sandpaper, or do I have to get them turned no matter what?
You can remove the surface rust with fine grit sandpaper and be fine. If your drums are pitted anywhere on the braking surfaces, you should have them turned. Just to be sure they're up to the task, grab a manual for your car and find out the maximum inner diameter of the drums and measure them or have them measured. If they've been turned out too much you'll have troubles.
If you take them to a reputable shop and ask them to "very lightly dress them up", you shouldn't lose any appreciable amount of iron. You will also improve the break-in and fit of your new shoes. Making sure the drums are perfectly round, and having a uniform texture will give you a better brake job. You can get away with less, but why?
mike's rite,also get your new shoes ark fit to your drum,it make them work way better right away,any good auto parts shop can ark them,if it the one you buy shoes from it may even be free. The Bat miami need 42to48 frontaxle****m. in fla.
I always turn my drums. It's not just scoring or even pitting. I don't panic over minor pits or a small score after turning on my personal drums. Customer drums are a different subject. Drums are prone to warp from the heat. If they are out of round, you will get a pulsation in the brake pedal and uneven braking. You can't see it with the naked eye. The only way to tell is to put them on the drum lathe and turn them. If they aren't out of round, it will only take a skim cut to restore the braking surface. If they are warped you'll be glad you had them turned.
most drums and some rotors have a beveled edge, as long as there is bevel left, they are not turned too far. of course, deep grooves will throw all that out the window.
i always have them turned. granted dad has like 3 brake lathes, but i usually do 1 what they call "rough" cut which is fast, but gets the high level grooves out if the person has been riding onthe pads/shoes metal.. then a finish cut. i do it because, its free...and while im doing the rest of the brake job the drums are turning themselves. also, thank god for white lithium grease....my father is***** about doing brake jobs, never wants a come back for a squeek or anything, the white litium on anything thats going to rub together but the shoes/pads is a lifesaver.
I'd clean them up with sandpaper in the 150-240 grit range. If you want to "do it right", then measure the inside diameter of all 4 drums using a ruler, and take the smallest ones in to a machine shop and get them turned. I didn't think the brakes on those cars worked well enough to wear the drums....let alone get them hot enough to warp!
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