The Stovebolt Site Forums The Shop Area Driveline Disk brake conversion

I’ve been looking at disk break conversion kits for a’63 C30 step side. I’m finding c20 kits but nothing for a c30. Any one know if C30 conversion kits with 8 lug rotors?

Joe

Cadillac converters and disk breaks. Both hard to explain.

Have you looked here?
https://tuckersparts.com/product/Disc-Brake-Conversion-Kit-F-8LUG/

At https://www.67-72chevytrucks.com there is a suggestion to swap the entire front suspension for an 1981 GMC.
Maybe other swaps are possible.

Thank you Buoy. I’ll check them out.

Joe

What's the reason for the conversion?

I was kinda wondering the same thing? I drive a 66 c20 on a 63 GMC 1 ton chassis with a stock drive line. I've had 3k lbs on the bed of it at the scrap yard and didn't have one bit trouble stopping. Drum brakes work well if properly adjusted and serviced. For the time and effort, not to mention cost, it might be worth a second thought about servicing what you got.

If the drum breaks were that bad, how in the world did any of those trucks survive for 50 years or more of running max weight loads (or more likely big overloads) every day, so a hotrodder could decide he needs to convert to disk breaks? They should have been totalled a few weeks after they rolled off the assembly line. Yes, the spelling errors are intentional!
LOL!
Jerry

Q. And why do dump trucks, delivery trucks and tractor trailers all use drum brakes?
A. Because of their superior stopping power and shorter stopping distance.

The only advantage disc brakes have over drums is that they don't heat up and fade during repeated, high speed, panic stops. Unless you're auto-crossing your vehicle, drums work perfectly fine.

I have stock brakes on my AD 1/2 ton and they work well, but wonder that if drum brakes are so good, why did the manufacturers switch to disc brakes? Are they cheaper? Cars got more powerful then got disc brakes. Fifty to sixty years ago, everything coming out of the factory had basically the same technology and people probably drove closer to the speed limit than they do now. But now, these classic vehicles are sharing the road with higher powered ICE cars or electric cars that go from zero to sixty in 3 seconds. Then add in Mr. Important who is better than the rest of us by darting in and out of traffic to get 2 car lengths ahead of you, so the possibility of quick stops could be higher. Doing a search online reveals contrary opinions as to what is better. Seems that both systems have their pros and cons.

Discs have fewer parts and are cheaper and easier to install so manufacturers like that aspect because its more profitable for them.

You aren't driving an antique vehicle to its limits and are not making repeated high speed stops. By that I mean decelerating from highway speed multiple times in less than a minute as on a race course. That just doesn't happen in normal driving scenarios. If you're in the habit of riding your brakes down mountain roads, then disc brakes won't overheat like drums. But who does that in an antique car?

Stopping distance is longer on disc brake equipped vehicles than drum equipped vehicles of the the same weight.

I read a comparison of a Ford Taurus and a mid 50s Ford of approximately the same weight and the 50s Ford stopped about 20 feet or so shorter from 60mph than its modern equivalent.

If you're worried about stopping distance, drums are your friend. Again, its a 70 year old truck. How fast are you driving and how close are you following the guy in front of you?

As I mentioned before, heavy vehicles such as dump trucks, semis, delivery vehicles, etc are all equipped with drum brakes because they stop quicker than discs.

The drum brakes on my 37 Buick served me well for 40 years UNTIL I got caught in Kansas City during a monsoon. The drums were actually under water and though I had full pedal I had no brakes. For 99% of people with vintage rides I'd stay with drums but mine gets driven from coast to coast and Mexican to Canadian border including traversing the length of the Grand Teton mountains. Just one 40 year event had me put on front discs so I will always have stopping power regardless of conditions. It would take a really big guy or at least a small gun to force me to go back to all drums.

Exception: California!

1 question, 1 answer, and 9 replies accomplishing... what exactly?

Well, this is a discussion forum. One question can result in one or more answers, but often the topic opens up other thoughts and contributions. This question could be read by someone who might be thinking about doing the same conversion. People adding input but not answering the question could cause someone else to think that maybe they should investigate this further. That is a part of learning (IMO). Many conversations on Stovebolt have one answer plus many opinions (i.e. things to think about').

I was thinking of converting to disc brakes for my ‘49 AD Chevy PU, now I’m questioning if I should. I was confused about all the different conversion kits so haven’t done it yet. I would be mainly driving my truck on country roads and around town. Thanks for your input and advice!

Exactly! Thank you! You just described me! Please read my contribution to this thread.😁

Suzie Q,

What do you hope to achieve by converting to disc brakes? Are you having specific problems with your braking system that you attribute to the fact that they are drum brakes?

I ask because many people are under the misconception that disc brakes "stop faster". This is not true. Disc brakes often increase stopping distance compared to a properly operating drum brake system. That's why tractor trailers and concrete mixers, etc all use drum brakes.

Discs don't overheat and fail as rapidly under high speed panic stops or multiple hard brake applications as you might encounter in motor sports. Does this reflect your driving style in an AD truck? Do you ride the brakes down Pike's Peak regularly?

Disc brakes are easier to work on when replacing pads as opposed to shoes. If you aren't doing the brake maintenance yourself, then it doesn't matter.

A more important upgrade to an AD truck's brake system would be the installation of a dual reservoir master cylinder simply for safety's sake and peace of mind. Nearly all my vehicles have single reservoir systems and I've never had a problem with any of them.

If you're like most people who own and drive antique cars, you are probably intimately familiar with your vehicle's mechanical components and their condition because you're opening the hood all the time and checking things out before driving the vehicle. This attention goes a long way toward avoiding the problem associated with a single reservoir brake system.

Just so you know, I have a 1950 3100 with the stock single reservoir, 4 drum setup. I use the truck regularly and have driven it over 2000 miles in the last 6 months. This is driving on country roads, interstate highways , and everything in between. Average speed on the highway is about 55. Average speed on secondary roads is about 40.

Not once did I ever worry that the stock brake system wasn't up to the job. All I ever drive are antique cars and I don't pussyfoot around in them but I don't "over-drive" them either. I know their capabilities and limitations. I never expect a 70 year old truck to behave in the manner of a 2023 truck (as many people sometimes do with fully restored old cars). I am fully aware that it's 70 year old technology and treat it as such.

Thanks again for your reply. Yes, I guess I took the “Kool-Aid” and was thinking a disc brake upgrade would make my truck stop faster. BUT, to my credit, I haven’t ordered anything yet because I wanted to get the opinion of experts on this forum. You’re talking with a novice, (an RN), not a mechanic! Lol

I'm no expert but I do have a lot of experience with antique cars. It's all I've ever known so I don't pine for modern "conveniences".

Has anybody installed a heated steering wheel on their AD truck? I think I want one. NOT!

I did a front disk brake conversion on my '50 3600 but my rational was related to parts availability (drums were Huck) and self adjusting benefits. I'm my own mechanic but adjusting drum brakes to keep them working as intended is rarely done as often as needed to maintain stopping performance. My rears are drum but came with the Chevy 14-bolt rear axle swap. Anyone intersted in some used Huck front brake parts let me know.

WICruiser,

You could offer those "Huck" parts up in one of the Swap Meet forums. There have been a few recent ads looking for "Huck" parts in "Truck Parts Wanted" forum.

With that said, back to the topic of discussion.