Turning drums

Is it necessary to have new brake drums turned before installation?

 

no. just make sure its cleaned with degreaser.

 

thanks.

 

They don't necessarily need turned, but should be checked for true and turned as necessary to correct any defects.

 

What 61bone said. I had a brand new rotor almost shake my teeth out the first time I stepped on the pedal. They're not always true when they come off the boat.

 

Yes, 61bone is right. I've had a lot of experience with cheapo house brand drums and rotors and there's always the chance that they are not true. A little pre-check will save a headache later.

 

We used to arc/true the shoes to the drum. Is that still recommended?

 

Roundvalley,
I would say 'no' if the drums and shoes are new.
But if you put new brakeshoes in used drums if would be advisable to do so yes.
And again what's been said earlier, it never hurts to check everything out, even with all new parts.

 

Do it. You want be sorry.

 

Check it for sure, I can't count how many new "Chinese" parts I install or mock up that don't quite fit or in this case, be true and round.

 

Personally (20+ years), I cant remember installing a new drum on a customers car that wasn't round out of the box. Rotors - installed quite a few that were aldready warped straight out of the box.

If it were my own car I wouldn't turn them but then again, I have access to a brake lathe so if I make the wrong choice, it costs me only my time.

 

When I was a mechanic for Ford & Chevy I did mostly emgine work and many brake jobs . I NEVER put a new drum or rotor on without turning them . In almost all the cases they were out of round . Most were very close but not too bad but some were awful ! Why take the chance by doing all that work and it being out of round . Good brakes is the most important thing on the car you depend on the most ! Just my 2 cents worth !

 

Also check that they are "centered" I have purchased ofshore drums that were core shifted.

 

When I started helping my buddy at his brake shop almost 30 years ago now, I used to be the designated drum/disc turner. It was a classic old fashioned quality shop that always turned new drums. 5 bay high volume shop. I never found a new drum that didn't need a slight cut. He insisted that new ones got trued. Some were worse than others. Some you would probably never notice but I never saw a perfect new one. Can you get away with out truing them? Probably but if you do enough you will be bringing one back in to true both rear drums to make sure that you got the culprit.

 

After 25 years in auto parts I can say that I never sold a true drum or rotor.
Raybestos and Wagner where close , but when the China crap started showing up it was not uncommon to take .030 out/off to make it round or true.

 

I turned every one I ever put on and never once was there a perfect one. When you do it for a living and when you have to do it again free if it isnt right you very quickly learn what to avoid. Green castings are a big problem expecially brake drums. if it is your own and you dont mind doing it twice you could take a chance but customers have a very dim view of jobs the require two trips
Don
Re shoe arc. it gives a firm brake pedal right away and makes for a very nice job but very few shops have them anympre

 

It's hard to find a place that can do it any more or even knows what you're talking about..

 

That's because all the old timers who arched brake shoes died of lung cancer from the asbestos in the grindings they were breathing. I think OSHA stopped that.

 

Good point.

 

I have them turned, and have the shoes matched to the curvature. You dont have to, but it seems to stop a little better this way. I think Ed's auto parts in covina still does it.

 

Put those Chinese drums in that American lathe and do it right.