Oversized Brake Drums

[CA Victoria]

I am working on putting together a set of 1935 Ford mechanical brakes & drums.
There are two different camps when the topic of brake drums comes up.
The warning comes to not use brake drums if turned beyond 12.060 stating it is dangerous. Why?
The folks who have worked on these for years will cite using drums turned well beyond 12.060, none so far can remember a drum failing?

The drums I have turned to 12.100 have about .110 wall thickness.
So is the warning because of drums failing, or overheating, or warping?

Several shoes I have removed have paper like shim material under the lining to compensate for the drum diameter. I have not found thicker woven lining so I have made .030 metal shims to use with woven linings.

Lots more experience here on The Barn than I have.......so do you see any pitfalls with using oversized drums with shimmed linings?
Any one with experience of drums failing?

Thank you!

[51504bat]

Get involved in an accident even if brakes weren't an issue, having drums in excess of the maximum is looking for a lawsuit. JMHO.

[Branded]

Originally Posted by 51504bat

Get involved in an accident even if brakes weren't an issue, having drums in excess of the maximum is looking for a lawsuit. JMHO.

Never have I heard of anyone ever having someone wanting to measure brake drums for being overturned after an accident.

[51504bat]

Originally Posted by Branded

Never have I heard of anyone ever having someone wanting to measure brake drums for being overturned after an accident.

I spent almost 8 years as an investigator for the California Department of Transportation's Legal Division. The last 2 1/2 years as the supervising investigator in charge of all law suit investigations pertaining to vehicle (and other) accidents. It does happen. The California Highway Patrol Multi Disciplinary Accident Investigation Team (MAIT) conducts lengthy accident reviews which focus on all factors that may have contributed to the cause of an accident, including brakes.

[Branded]

Originally Posted by 51504bat

I spent almost 8 years as an investigator for the California Department of Transportation's Legal Division. The last 2 1/2 years as the supervising investigator in charge of all law suit investigations pertaining to vehicle (and other) accidents. It does happen. The California Highway Patrol Multi Disciplinary Accident Investigation Team (MAIT) conducts lengthy accident reviews which focus on all factors that may have contributed to the cause of an accident, including brakes.

California, that just explained it. 🙂

[TJ]

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Originally Posted by Branded

Never have I heard of anyone ever having someone wanting to measure brake drums for being overturned after an accident.

It depends if there was a fatality or major injuries. The police may do it in the case of a fatality or the insurance investigator may do it when there is a law suit.

[V8COOPMAN]

Originally Posted by TJ

It depends if there was a fatality or major injuries. The police may do it in the case of a fatality or the insurance investigator may do it when there is a law suit.

That makes it simple. Just don't get involved in a FATAL accident, and just refuse to let anybody file suit against you! DD

[Kube]

Originally Posted by Branded

Never have I heard of anyone ever having someone wanting to measure brake drums for being overturned after an accident.

In Illinois back in early 1980's, two folks were killed when a persons brakes failed and they were run over.
The person driving was eventually jailed. It was quite the sensation back then making a lot of the national news outlets.
It also changed a lot of ways of doing business.
No more oversize brake shoes were sold and no more "lesser quality" aka "economy" shoes / pads were sold to those trying to go "cheap". Only pads / shoes manufactured to the minimum required by the car maker were to be sold after that debacle.

So, now you have heard...

[Frank Miller]

Originally Posted by Kube

In Illinois back in early 1980's, two folks were killed when a persons brakes failed and they were run over.
The person driving was eventually jailed. It was quite the sensation back then making a lot of the national news outlets.
It also changed a lot of ways of doing business.
No more oversize brake shoes were sold and no more "lesser quality" aka "economy" shoes / pads were sold to those trying to go "cheap". Only pads / shoes manufactured to the minimum required by the car maker were to be sold after that debacle.

So, now you have heard...

Brakes can fail for many reasons, even driver ignorance. One big no no that people have done is compression fittings on brake lines. A parts store did not want to sell me some compression fittings and a piece of brake line until I explained I was fixing my transmission lines.

[Kube]

Originally Posted by Frank Miller

Brakes can fail for many reasons, even driver ignorance. One big no no that people have done is compression fittings on brake lines. A parts store did not want to sell me some compression fittings and a piece of brake line until I explained I was fixing my transmission lines.

Frank, The parts store was actually following the law. I remain surprised that their training included this little tid bit.

Good for them and good for you

[Bob C]

Overheating and brake fade as in no brakes.

[CA Victoria]

I’m stuck on the application of a .060 limit to every drum ever made....
How thick are your brake drums after turning?
What is your experience?

Quote from another........
“Most drums are cast with enough thickness to allow 0.090" of wear. In other words, the difference between a drum's diameter when new and its discard diameter is 0.090," but that doesn't mean you can machine a drum right up to the 0.090" limit.

[papanomad]

most machine shops won't turn beyond .060.

[V8COOPMAN]

Originally Posted by papanomad

most machine shops won't turn beyond .060.

….only because it's ILLEGAL! You kill some baby with that 'old hot rod' and the Momma gets the 'right' attorney involved, they will tear that car apart looking for anomalies, and they'll make the remainder of your life unbearable! DD

[itslow]

Originally Posted by V8COOPMAN

….only because it's ILLEGAL

I suspect you'll have a hard time finding any federal or state laws that prohibit drums from being turned to an ID greater than .060" oversize.

Laws will be written to prohibit exceeding the drum/disc manufacturer's recommended minimum thickness, not some arbitrary measurement of .060" or such.

Manufacturer A's drums may only be able to be turned to 12.060", while Manufacturer B's drums may be able to be turned to 12.160".

[Talkwrench]

just be careful if youre oversize , you'll need oversize linings to match, dont just buy off the shelf and expect them to work.

[deuce_roadster]

Doesn't even need to be an at fault accident. My son was T boned by a car that ran a stop sign (totalled a fresh restoration of my old 56 Chev pickup) 100% fault of the person who hit him. He was not injured thankfully but even so, the truck was taken to a shop and all 4 brakes were checked and measured. I kept a log of everything done on the truck and that was in the glove box, and everything I claimed I did was checked off as in good condition. If anything was off the insurance company of the person who hit him would not have paid anything and fought it in court. It is what they do, insurance companies have lawyers to do that and the average joe can't compete meaning afford to fight. They (after a year) settled for 30k but they strung it way out on something that was cut and dried, police issued a citation and everything.. It is false economy to use safety issue parts (steering, brakes, tires) that are not legal.

[bobH]

Some folks worry more that me. My wife was a fatality in a car accident. I followed her car from tow yard to junk yard, to junk yard, to a 'final' junk yard. I can assure anyone, that NO ONE ever came to inspect ANY portion of her car. And, I saw at least two things that I feel were manufacturers defects, that made her accident a fatal one. No one cared. And the insurance company paid promptly. My point being, some of the above posts present possibilities. But, seems to me, very unlikely. New or newer cars, yes, I wouldn't cut corners on drums or rotors. They are mostly inadequate when new, anyway. The shittiest brakes I've ever encountered, have been on modern, near new cars. I live in the mountains, and I've had at least two modern cars where I could warp the rotors on just ONE trip off the hill. But, for our 'old' cars, seems to me there is, and always was, a little extra margin. Obviously, opinion. And, goes without saying, I can predict opposing opinions.

[JSeery]

It seems odd to me that anyone would want to deliberately build a vehicle in violation of the law. This type of stuff is what leads to government inspections to the level of being ridiculous. There are legal limits on how much you can turn a brake drum. If I remember correctly there are drums that can be legally turned beyond .060, but these drums are clearly marked as such.

[J Franklin]

Originally Posted by JSeery

It seems odd to me that anyone would want to deliberately build a vehicle in violation of the law. This type of stuff is what leads to government inspections to the level of being ridiculous. There are legal limits on how much you can turn a brake drum. If I remember correctly there are drums that can be legally turned beyond .060, but these drums are clearly marked as such.

Doing shoddy work that can be called out after an accident will also give our hobby a black eye. It might also lead to targeted regulations.