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Brake Drums out of Round?

MomoJeep

MomoJeep

Basic User
City
Seattle
State
WA
Is it normal for new drums to be a little out of round? I just put new ones on (11" conversion), and there's an initial adjustment to be made. Spinning the tires and turning the little star-wheel adjuster until is stops the tires from turning, then backing off until the tires turn again. Problem is, when I spin my tires the brakes drag a little in one spot for each rotation. So this makes it hard to adjust.

But it also makes me wonder, did I get bad drums? Are they warped. out of round? Or maybe they are not perfectly centered even though the lug nuts are quite tight?
 
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Is the problem with just one drum or both (if just one you could swap them and see if the dragging occurs on the other side). A brake/machine shop should be able to test the drums for run out to see if they're warped (this would be unusual on new drums in my experience). Could also be that an axle shaft is a little bent (not unheard of on 35 year old axles).
 
Both sides. I have 1-pc axle conversion, so the axles are not that old. But good point! The guy at the parts store said he wouldn't be surprised if the BOTH are warped. He said sometimes when parts aren't good, they come in "batches". I honestly don't remember this many problems with quality when I was younger.
 
Check to make sure you have the shoes in the correct position (front/back). I had one switched and this was the symptom.
 
It depends on where you get them from. By me the AutoZone drums are great. But at Advance they are out of round at LEAST 9 out of 10 times. I have to cut them to make them right.
 
When i bought my drums from napa 27-28 years ago they were lifetime. When i went 3 years ago they were 1 year and Chinee
 
I went by my local brake shop. They said not to worry about it, that it was minor and that the shoes will wear out the "high spots" first and the drums will come into round. Makes sense. However.... It really sucks that it's very hard if not impossible to find high quality parts. Especially when we are working on classic vehicles, not disposable cookie cutters. If there was one company that made good stuff, I'd always buy those products.
 
Problem is we got into a mind set a long time ago of getting everything for the cheapest we can. In the government arena it is called "low bid speck". Dose not always mean the cheapest or the best quality of an item.
 
MomoJeep said:
I went by my local brake shop. They said not to worry about it, that it was minor and that the shoes will wear out the "high spots" first and the drums will come into round.
Click to expand...
Just a thought... if the shoes are running on "high spots" then you are not getting the full braking capacity that you will get once they are worn in.
This is in reference to your other post on questioning feeling the difference from the upgrade.
 
I wouldn't play games. I'd take them to a shop and have them turned. If it just a minor high spot, you won't take that much off. Hopefully you'll still have a good, long life with them. Not worth waiting for them to wear to wait for them to hopefully wear round. I remember many years ago you would have the new drums turned just to make sure they were true and you had a clean surface for the new shoes.
 
I had a bad brake drum on my boat trailer 10+ years ago. Lost 4 tires on that drum in one trip. Caused me to rip out the brakes and install a non brake hub to finish the trip. (Nothing more enjoyable than going 50 miles, change tire, go 50 miles, change tire, go 50 miles, leave trailer on side of the road to go buy 2 new spares, change tire, go 50 miles, change tire and remove drum brake backing plate leaving only the drum on the spindle, then continue trip with no more issues. All that with top shelf good quality trailer tires, Cooper at the time, too bad they are no longer made. I have not found any trailer tires that are half as good as those were.)

Don’t run a bad drum, get it fixed by getting a replacement or having it turned.
 
I'd also try to have them turned to even out the surface (or return them for another set - just on principal that they should be made right in the first place). Don't want any pulsing in the brakes.
 
Well it's hard to describe the "degree" to which they are not perfect. I'm talking about spinning the tire by hand and noticing it spins totally free for part of one revolution, and slows down and drags a little for the rest of the revolution, where I have to push a little to get it to keep spinning. When driving I don't feel any pulsing. The guys at the brake shop didn't think it was an issue. But I would prefer it to be perfect. Do you'll think that small of a "drag" is worth turning/replacing?
 
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