Turning Brake Drums

[Memphisdoug]

I want to get the surface that the magnets ride on turned on my brake drums. Is this something that a shop that turns brake rotors and non-trailer drums can do or do I need to look elsewhere?

[ktmrfs]

I called my favoritge machine shop about a year ago about turning trailer brake drums. AS others have said, turning the magnet surface depends on what equipment they had.

First question he asked was "do you want the friction surface turned or the magnet surface turned?" when I said friction surface he said yup, but I CANNOT turn the magnet surface, don't have the equipment.

[Lynnmor]

smkettner wrote:
I think if I was buying ALL new stuff it would be disks.
That is the trouble with this RV stuff. For a few $$ more....

I think you are right. I went thru too much of this junk and now realize that I really wasted too much time and money on trash.

[time2roll]

I think if I was buying ALL new stuff it would be disks.
That is the trouble with this RV stuff. For a few $$ more....

[Lynnmor]

Memphisdoug wrote:
Well, I checked around my area for places that turn drums and rotors. The ones that do were unable to turn the armature face of my drums. Based on what I have read, the drums I have are in too rough of shape to use with my new brake assemblies. Therefore, I put in an order with etrailer.com for 4 new drums. That way, the whole braking system will be new and should work like new.

Did you order new bearings? I did and had serious problems. Some information here: bearings, etc.

[Memphisdoug]

Well, I checked around my area for places that turn drums and rotors. The ones that do were unable to turn the armature face of my drums. Based on what I have read, the drums I have are in too rough of shape to use with my new brake assemblies. Therefore, I put in an order with etrailer.com for 4 new drums. That way, the whole braking system will be new and should work like new.

[Boon_Docker]

You were previously talking about max inside diameter, so you did not understand what the OP wanted.
I replaced brakes complete last year and purchased 10 inch drums from Napa for $35 each, which is at least what it would cost to have the armature refaced per drum. Real world Canadian prices, not from 20 years ago.
If you think you can get the drums refaced for less than that price then let the OP know where.

[Gdetrailer]

Boon Docker wrote:

Gdetrailer wrote:

Boon Docker wrote:
You can buy new drums for $40-$50 each c/w new bearings. I bet that it would cost about the same amount to turn them, if you could find a place that would do it.

No, it doesn't cost as much as new drums..

Last time I had a auto drum turned it cost about $10 per drum, that was at least 20 yrs ago.. Might expect $15-$20 per drum now days..

If the drums have enough meat in them and you are turning 4 drums at $20 per drum you will spend $80 vs $200 at $50 for new drums..

There is nothing wrong with having a drum turned provided it is not worn past the max inside diameter.

The only reason to replace is if it will require to much removal of material past the max diameter or the drum is too far out of round.

People now days have gotten rather lazy and are willing to pop for new drums..

He is not wanting to have to brake surface turned, he wants to turn magnet surface. Whole different ball game.

Wow, you need to migrate to the modern world. What cost $10 20 years ago would cost $30-$40 today, if it were only the brake surface that was being done.

No, I FULLY UNDERSTAND that the OP ONLY wants to have the MAGNET SURFACE turned.

I have now mentioned MULTIPLE TIMES that not all drum lathes have the capability to REACH the magnet surface, therefore making it even harder to find a place that can surface the magnet area.

And YOU need to get out of CANADA for real world prices, machining drums does not cost $40-$50 US Dollars unless you are having a dealer do it for you..

The problem is finding a place that still turns drums, many shops are setup for ROTORS and have lathes that mount on the vehicle. Drums on the other hand are not as common as they used to be. But I still do have a NAPA store nearby that does have a drum lathe..

[Lynnmor]

I turn my own drums and armature faces. If you can find a shop to face your armatures, be sure that they can get a very smooth surface. If that surface does not have a good finish, the magnet will start to chew into it and will quickly develop grooves. See Dexters information: Dexter

If you get new drums, the magnets need to be resurfaced or replaced. New drums may have quite a bit of run out. I made mine much better than new.

[mbopp]

Try looking for a shop that does clutch and brake relining. I asked - the local clutch rebuilder has a lathe that will do both surfaces on a trailer drum.

[wa8yxm]

I will support the "Depends" post

Some shops can do it. Some can not, That simple.
I know HOW to do it, but alas knowing how and having the tool needed.. Two very different things.

[Kayteg1]

Boon docker wrote:
He is not wanting to have to brake surface turned, he wants to turn magnet surface.

OP wrote:
I want to get the surface that the magnets ride on turned on my brake drums

and some say that with my 3rd language English I have hard time to understand it.
Coming to original question, I ditto the suggestion than new drums made in China cost less, than turning Chinese drums in USA.
Get new ones and forget it.

[Boon_Docker]

Gdetrailer wrote:

Boon Docker wrote:
You can buy new drums for $40-$50 each c/w new bearings. I bet that it would cost about the same amount to turn them, if you could find a place that would do it.

No, it doesn't cost as much as new drums..

Last time I had a auto drum turned it cost about $10 per drum, that was at least 20 yrs ago.. Might expect $15-$20 per drum now days..

If the drums have enough meat in them and you are turning 4 drums at $20 per drum you will spend $80 vs $200 at $50 for new drums..

There is nothing wrong with having a drum turned provided it is not worn past the max inside diameter.

The only reason to replace is if it will require to much removal of material past the max diameter or the drum is too far out of round.

People now days have gotten rather lazy and are willing to pop for new drums..

He is not wanting to have to brake surface turned, he wants to turn magnet surface. Whole different ball game.

Wow, you need to migrate to the modern world. What cost $10 20 years ago would cost $30-$40 today, if it were only the brake surface that was being done.

[Old-Biscuit]

Face of drum when magnet rides need only be flat/clean enough to 'attract' magnet and hold it enough to rotate so brakes shoes can engage.

Magnet only move 3-4" and then 'slides' on face of drum as it rotates.

Few places have the set up on their brake lathes to machine that inner surface for magnets.

I usually just use crocus cloth or emery cloth and hand sand that inner surface to clean it up

[time2roll]

Yes price a new drum shipped before you go to the shop and spend money.
ALL shops that turn a drum and know their salt can turn the magnet surface.