Brake Drum Replacement

[James R.]

One of my front brake drums needs to be replaced. It is pretty warped and has been ground down to the max. It looks like someone ground down the rivets (drum face side) and then welded the holes over. I think the heat generated may have warped the drum. I have ordered a replacement drum. Has anyone out there re-attached the hub to the front drum? Where can I find the rivets? My thought was to use an air hammer to knock down the rivets once they are inserted...any ideas/thoughts? Or, is using bolts/nuts to attach the hub to the drum an acceptable alternative? My car is a 58.
Thanks,
Jim

[Joe L.]

Re: Brake Drum Replacement

One of my front brake drums needs to be replaced. It is pretty warped and has been ground down to the max. It looks like someone ground down the rivets (drum face side) and then welded the holes over. I think the heat generated may have warped the drum. I have ordered a replacement drum. Has anyone out there re-attached the hub to the front drum? Where can I find the rivets? My thought was to use an air hammer to knock down the rivets once they are inserted...any ideas/thoughts? Or, is using bolts/nuts to attach the hub to the drum an acceptable alternative? My car is a 58.
Thanks,
Jim

Jim-----


If it were me, I would not attempt to re-rivet the brake drum to the hub. You might end up creating more problems than you solve and, actually, I don't think you'll solve any problem, at all. The lug bolts and nuts are sufficient to retain the system and, for drum brakes, nothing is really gained by attempting to re-rivet the drums to the hubs.

By the way, if it were me and one front drum was bad, I'd replace both front drums. However, out of the 4 cars I have (only 2 of which are Corvettes), I don't currently own even a single drum brake. So, I won't be faced with this anytime soon.

[James R.]

Re: Brake Drum Replacement

Joe,

Thanks for the reply. I'll skip the re-riveting. Why would you want to swap out both front drums if only one is bad? I'm not much of a mechanic...
Jim

[Joe L.]

Re: Brake Drum Replacement

Joe,

Thanks for the reply. I'll skip the re-riveting. Why would you want to swap out both front drums if only one is bad? I'm not much of a mechanic...
Jim

Jim------


First of all, I suspect that if one drum is bad, the other probably isn't far behind. Most likely, it's been previously machined, too, and may be at its wear limit.

Most important, though, is the fact that I think you stand a much better chance of having a smooth, non-pulling braking action if the front drums are matched. There are "intangibles" in braking performance such as surface finish of the drums.

[Duke W.]

Re: Brake Drum Replacement

I'm not sure if this applies to C1s, since they preceed my time as a GM production engineer, but drums were typically held onto knuckles and axles with a single stamped spring nut - basically a small, very thin belleville washer with a serated ID that threaded onto a wheel stud.

The purpose was to keep the drum secured to the knuckle/axle assembly during shipping and handling. It was totally unnecessary for the assembled car, but was usually not removed as part of the assembly process. It was thin enough that it didn't interfere with proper wheel seating against the drum

The first time the drum was removed for service these "nuts" were typically thrown away by the servicing organization - dealer or independent.

It's possible that the rivets you refer too provide the same function and are not necessary unless they are visible during the judging process.

Drums/shoes, disks/pads should usually be serviced in pairs on each end of the vehicle as Joe explained. Otherwise uneven braking can be a consequence. It sounds like you need to give all your drums/shoes a thorough inspection and decide what work is needed to bring the system back to serviceable condition.

Duke

[James R.]

Re: Brake Drum Replacement

Thanks. I have completed a total overhaul of my brakes...new shoes, hardware etc. I turned my rear drums with no issue. I was in the process of turning the fronts when I noticed the warpage of one of my drums...close inspection showed the welds holding the hub to the drum. The other drum, although had been turned in the past had a nice smooth braking surface and was not warped. I thought I could get away with replacing the bad drum...I don't want bad braking characteristics and if the best plan is to replace both drums, then, that is what I will do...I am putting together my rolling chassis, so, this is the time to get it right.
Thanks again,
Jim

[Duke W.]

Re: Brake Drum Replacement

This is a gray area. You have one good, but turned drum, and one drum that is new.

In severe braking the turned drum could overheat and fade before the new drum due to the turned drum having slightly less thermal capacity, and this could cause noticeable pull.

But unless your driving style requires frequent heavy braking this will probably not be an issue.

However, since C1 generic replacement drums are inexpensive and interchangeable front to rear, my recommedation is to replace both front drum and keep the good, used drum as a serviceable spare. You can never be too careful about servicing the brake system.

Duke

[James R.]

Re: Brake Drum Replacement

Good advice Duke. As I mentioned, I'm not much of a mechanic...but, I'm "trainable."
Jim

[Joe L.]

Re: Brake Drum Replacement

I'm not sure if this applies to C1s, since they preceed my time as a GM production engineer, but drums were typically held onto knuckles and axles with a single stamped spring nut - basically a small, very thin belleville washer with a serated ID that threaded onto a wheel stud.

The purpose was to keep the drum secured to the knuckle/axle assembly during shipping and handling. It was totally unnecessary for the assembled car, but was usually not removed as part of the assembly process. It was thin enough that it didn't interfere with proper wheel seating against the drum

The first time the drum was removed for service these "nuts" were typically thrown away by the servicing organization - dealer or independent.

It's possible that the rivets you refer too provide the same function and are not necessary unless they are visible during the judging process.

Drums/shoes, disks/pads should usually be serviced in pairs on each end of the vehicle as Joe explained. Otherwise uneven braking can be a consequence. It sounds like you need to give all your drums/shoes a thorough inspection and decide what work is needed to bring the system back to serviceable condition.

Duke

Duke-----


I believe that early C1's had the front hubs riveted to the drums. I thought this ended after 1957 but it may have continued beyond that.

[John F.]

Re: Brake Drum Replacement

Call me stupid if you will, but I never heard of a drum being riveted to anything. Could you post a picture of what you are talking about???
John

[Dan D.]

Re: Brake Drum Replacement

They are riveted. My 57 is riveted, and I had a hard time finding someone that could chuck ball bearings in order to turn them down. Most hubs are roller, - ball wheel bearings have not been used in years. -Dan-