Just thought I would share this info with you guys.
As most you know it is almost impossible to find brake drums or rotors for our trucks that are made anywhere but China. China's QC generally leaves much to be desired. Because our trucks use captured brake components it is a real hassle when you get a drum or rotor that is unbalanced and you have to replace it with one that you hope is ok. I have read MANY stories of people having to replace multiple drums or rotors until they get a good one.

I recently ordered a set of Raybestos 1961R drums from a seller on Ebay. They were $100 shipped to my door which is about $60 less than they would have cost at my local Advance. I When they arrived one of them had no balance weight welded to it and that concerned me.

I took them to my cousin's shop and he spun them on a Coates tire balancing machine. He input the measurements as close to a rim size and style as possible. One was .75 OZ off which I decided I could live with. The drum with no weight welded to it was 2 oz off. My cousin stuck 2oz of stick on weights to it, spun it again, and it came back balanced. My cousin said that if it wasn't actually balanced the machine would have indicated that the drum was unbalanced in a different location when he spun it with the stick on weights.

I peeled the stick on weights off and welded a steel weight on. I made the steel weight out of a piece of bar stock that I heated up and hammered a curve into it to match the drum. I cut the steel weight to 1.5oz to account for the welds.


The point of the story is that you can potentially save yourself a lot of hassle by having drums balanced before installation. Another thing to consider doing is to put the drums on a brake lathe and check them for true, or out of round conditions.

 

I remember when Chinese junk was a boat.

 

I like the idea of balancing the drums themselves, cool idea.

 

Freaking sad..... soooooo sad...

 

Aren't the drums cast iron? I know that takes some extra work to weld. Pre-heat, weld and post heat (I believe) and slowly reduce the temperature to ambient to prevent cracking. Where can you find an oven big enough? Besides the kitchen .

 

I had the same thought but the other drum was obviously stick welded. Obvious because of the slag all over the welds. They could have been welded on while still hot but I doubt they would have spun them while glowing. I think the cast iron in brake drums is more able to take heat than say a bracket. It didn't seem to negatively affect anything. Guess I'll find out when I heat the brakes up. Hehehe.

 

Part of the reason that I balanced the brake drums is that years ago while I was beating one of the drums off my 1995 CTD I inadvertently knocked the balance weight off of it. I didn't think much of it (it was only spot welded on) and put the drum back on the truck. At 15mph I noticed a thumping sound. At 25mph it felt and sounded like someone was beating on the rear axle with a sledge hammer. I never would have thought an unbalanced brake drum would have made such a ruckus. I replaced the drum with a new, balanced, one and everything went back to normal.

 

I welded some bracing on a Dana 44 once. Stick welded with some rod with a high nickle content. It worked good.

 

Not all Chinese ideas are junk but it is buyer beware. I watched a program years ago on their manufacturing process one shop look like its was out of the 30's the next shop was state of the art, the second problem they will show you what steel they used and as soon as you turn your back they use crap. But if you want quality brakes you will pay EBC is one, European steel is the best just ask a machinist mine down the road from me confirmed that !

 

I've been having a problem with low pedal. Bet it's just out of round or true in the drums and disks.

On checking with a local mechanic, he said he won't mount a new disk or drum without truing it up on the lathe first. Just prevents call backs. Doesn't even charge for the lathe time.

Next round will be a complete rebuild, and the cast parts are going to the shop first.

 

It used to be SOP to take new drums and rotors to the machine shop to have them trued up before installation. I don't know what ever happened to that...Mark

 

My own experience is a little different.

I run the drums for a while. If they become evident that there is an issue, I then remove and have them trued up.....

WHy ?


Because heating / braking / wearing in will distort the drum a bit. If it's machined from the factory, and heat is applied, they get out of round anyway. By heating / using / breaking them in first, then I get to have a drum that's "seasoned", and then trued up, vs just re cutting a new drum.


Now if I had a drum lathe in my garage, you'd be darn tootin I'd have it on there right out of the box.

 

Since most drums and rotors are now made thin enough that they can't be turned without putting them out of spec most places can no longer turn them. They also assume that all of them are like that. The brake lathe at my cousin's shop sees very little use for that reason. Most places don't even have a brake lathe anymore. Less labor to replace them that to cut them.

 

This is exactly my thinking.