Topic: Brake Drums

[carguytroy]

Have a late 67 Convertible c code I'm cleaning up and it has drum brakes all around. Im going through the brake system to make it safe to drive. Right now it's pretty scary. CAR HAS BEEN SITTING SINCE 1994. All of the drums have FOMOCO markings so I'm guessing they are original to the car. I am wanting to have them turned to true them up as they have some light grooves in them. This may not be the right place for this but does anyone know the tolerance for how far down they can be turned? And if they are not usable is there a good aftermarket source of the original style?

[jwc66k]

Take the drums to a brake shop, at least one you've had experience with. That's their business. Let them know that those are originals and you do want to keep them.
Jim

[67gtasanjose]

Take the drums to a brake shop, at least one you've had experience with. That's their business. Let them know that those are originals and you do want to keep them.
Jim

Two things are "true" about original brake drums but the most important one is once you cut the metal away, it cannot be put back.
The second thing is that a perfectly restored "machined" surface isn't "required" for qualifying a brake drum to be used in most "CONCOURS" applications.

What I am saying is that many drums can be cleaned up by simply machining off any outer groove or rusty areas and follow that with a "rotating" type cleaning up of the remaining surfaces WITHOUT lathing off the metal itself.

Front Drums might be a bit more delicate for vehicles that are DRIVEN OFTEN. Rear drums are a bit more forgiving if not perfectly restored on the machined surfaced.

Another thing to consider on brake drum machining is that the "finished diameter" should be close from one side to the other, (especially on the front brake drums again, this applies more to DRIVEN vehicles with FRONT brake drums).

Be careful WHO YOU CHOOSE to get these machined.

[Bossbill]

Have a late 67 Convertible c code I'm cleaning up and it has drum brakes all around. Im going through the brake system to make it safe to drive. Right now it's pretty scary. CAR HAS BEEN SITTING SINCE 1994. All of the drums have FOMOCO markings so I'm guessing they are original to the car. I am wanting to have them turned to true them up as they have some light grooves in them. This may not be the right place for this but does anyone know the tolerance for how far down they can be turned? And if they are not usable is there a good aftermarket source of the original style?

If they have light grooves, leave them alone. The brake material will wear into them. This will not affect performance.

[carguytroy]

Thanks for the replies. So what I'm getting out of the responses is clean them up best you can and pretty much don't mess with turning them. Makes sense. Preserve the original stuff. Would the original finish be black or just unfinished cast? The rest of the brake system looks to be original also. Wheel cylinders aren't leaking, yet anyway, and all the hardware/springs still have a little paint on them for the most part. 

[Bob Gaines]

Thanks for the replies. So what I'm getting out of the responses is clean them up best you can and pretty much don't mess with turning them. Makes sense. Preserve the original stuff. Would the original finish be black or just unfinished cast? The rest of the brake system looks to be original also. Wheel cylinders aren't leaking, yet anyway, and all the hardware/springs still have a little paint on them for the most part.

Original finish on the brake drums would be bare cast steel. Black out with a brush was typically for cars having open spoke wheels and not hubcap wheels where you could see flash rust in the back ground if left untreated.

[jwc66k]

Unfinished, with a dull grey finish. And for your own sanity, take them to a brake shop and ask.
Jim