The Stovebolt Site Forums The Shop Area Driveline Brake drum source

I have a 1950 half ton, and am preparing to do a complete brake job, to include replacing the master cylinder, wheel cylinders, brake shoes, brake drums, and a complete set of new steel brake lines. I've got every new part except the brake drums. I bought the shoes from Rockauto, but they didn't sell the brake drums. If I find them on a FLAPs website the prices are sky high! If anyone has bought drums lately at a good price I'd sure like to know where you got them. Thanks!!

Good luck with those. I've noticed the ones for 1950 are high as anything now. Can't yours be turned just enough to true them?

Lots of vendors sell them (Jim Carter, Classic Parts, Chevy of the 40's, etc) but you will have to pay between $80 - $120 each for them.

Jon G.... I’m certain all 4 drums have deep ruts in them and can’t be turned. I don’t want to replace everything but the drums and then complain afterwards that the brakes don’t work well.

Jhpv..... I’ll check those websites but hate that I’ll have to pay through the nose for ‘em! Maybe I should post a request in the “Parts Wanted” area and see if anyone has some they no longer need that they would be willing to part with.

Even a fairly deep groove in a drum doesn't necessarily compromise the stopping power, as long as the overall diameter isn't way oversize. If a drum can be cleaned up over most of its width with a relatively moderate oversize, leaving a groove or two doesn't present much of a problem. On those Huck brakes, matching the radius of the shoe to the drum is important. That can be done by gluing a piece of coarse sandpaper to the inside of the drum and scuffing the shoe into full contact and then removing the sandpaper. Using a water-soluble glue like wallpaper paste makes it easier to remove the sandpaper when you're finished fitting the linings to the drum.
Jerry

Thanks for the advice Jerry. I may be forced to have mine turned a bit and reuse them if I can’t find some good used ones. I’ve posted a request for some in the “Parts wanted” section of the swap meet area.

Question..... why can’t I use 1951 drums which are still available and relatively inexpensive? Is there *that* much difference??

In 1951 1/2-ton brakes changed to Bendix-style self energizing. The change included new drums.

What’s the physical difference between 47-50 and 51-54 drums? Enough that My 50 brakes would be completely incompatible or would they work but not quite as good as they should?

36-50 were for Huck brakes In 51 they went to Bendix..............

I'm pretty sure there's too big a difference in dimensions, either diameter, width, offset, or something, to use Bendix drums on a Huck brake. Otherwise, this parts availability problem wouldn't exist.
Jerry

Bendix brakes used 2" wide front shoes, versus 1-3/4 for Huck on 1/2 ton trucks. Rears were still 1-3/4, but there's probably some other dimension would prevent using Bendix drums on the rear of a Huck system.

Thanks Jerry and Klhansen for the replies, but I was hoping for more encouraging news. LOL If the front Bendix drums are wide enough for 2"shoes but the Huck's are only 1 3/4" then I'd think they would work fine as long as the other dimensions were the same. I wonder if buying a '51 Bendix drum locally to compare to my '50 Huck drum would be worth the trouble? Lord knows I've got nothing else to do while sitting inside here during the Covid19 lockdown in San Antonio! Trying to find a FLAPS that's open now would be my challenge.

At one time I had a master brake parts catalog that had a section with dimensions of parts such as wheel cylinders, master cylinders, shoes, drums, etc. I believe it got discarded when an assistant principal at the school where I was teaching decided to throw out the contents of some filing cabinets without consulting anyone. He trashed several decades' worth of repair manuals and parts books that were absolutely irreplaceable!

With a reference book like that. it might be possible to find a drum that would interchange, but I have no idea where one might be found. I believe that one was either for Wagner-Lockheed, or possibly Raybestos brand parts.
Jerry

My guess is the Asst Principal was a former Phys Ed teacher?

No humanities or shop teacher would have thrown that out. The Shop Teacher would have known better; and, the humanities teacher could never throw out a manual/book.

That might work if there was enough room for the 2" deep drums not to interfere with the backing plates. Doubtful that would happen.

As far as throwing out stuff, I'm always reluctant to do that. Someone will need it at some point.

Stay safe out there.

If the drum diameter is the same, you might be able to put a 1/4" spacer between the hub and the bolt circle area of the drum. That would shorten the lug stud length a little and space the wheel out slightly, but as long as you can get full engagement of the lug nuts, you might manage to get by with the swap.
Jerry

Both Huck and Bendix drums were the same nominal diameter (11 inches) for 1/2 tons.

We had a saying in the Nashville school system- - - - -"A principal is a coach with two losing seasons"! That's not as much of a joke as it might appear to be. School administrators in general tend to be failed teachers who have lips shaped just like the backside of the person a few rungs above them on the "career ladder"!
Jerry

I love your brand of humor Jerry!!

According to several Ebay listings, the same 1/2 ton 11" Bendix brake drum with 6 lugs fits Chevy and GMC from 1951-70, front and rear. It might be worthwhile to source a used drum from a salvage yard and see how much modification would be needed to adapt it to a Huck brake.

Brakes, and a lot of other parts are "dumb"- - - -they don't know what kind of vehicle or year they're mounted on. As long as they can be made to fit, they'll work. Back in the 1970's Dad adapted a set of 1/2" wider brakes to the Rambler Ambassador he used to tow our camping trailer. It made a huge difference in stopping power with the heavy trailer hooked up.
Jerry

At some point because of problems like this(good drums) we should start considering disc brakes, since almost all parts are readily available.

Ed

should consider?, or, might have to consider?

My 1954 3100 brake drums/parts are in excellent condition.
Over the past 25 years, I keep/kept my my eyes open for used/usable brake drums.
I have two spare sets of usable brake drums.

I hope my grandchildren will not have to worry about replacements.
(when I am gone in 30 years - I plan to live until 100, encouraged by Denny Graham).

I wonder how successful one might be at heating up a worn out drum and doing some makeshift spray welding into it to build it up
The material doesn’t need to be super strong or well adhered right?
I’ve thought about how I might do this on my own without much investment
I have many garbage drums to practice on

If anyone else had tried it or knows how
Please share
Thanks
-s

The essential part of any brake drum is its ability to transfer heat, evenly and rapidly from the friction surface where the linings contact it to the outside of the drum where the airflow over the drum can blow it away. I'd be a little reluctant to bet my life on something that had been built up and re-machined to have the same thermal transfer characteristics as an original, unmodified drum. I've heard on several occasions that an average stop from 60 MPH generates and transfers enough heat to melt a 9 inch cast iron skillet. The reason the drums don't overheat and/or melt is the incredible ability of that same cast iron to dissipate the heat to the surrounding air. That's why painting or powder-coating drums is such a dumb idea!
Jerry

okay that's something to consider
so i followed up on the heat transfer properties, good news!

most common mild steel mig wires, like AWS A5.18 Class ER70S-6, the carbon content is so low that you will be virtually matched in both heat conductivity and capacity to typical cast iron.
only if the carbon content is increased beyond 0.5% do the thermal properties of steel go down hill fast

cast vs mild steel at <0.15% carbon
55 vs 54 W/m*K
456 vs 465 J/Kg*K

now would the friction properties be similar? and if there were voids with slag, how would that change the situation?
-s

Good luck getting mild steel to bond to cast iron. You'll need some sort of nickel alloy MIG wire to flow and blend with the cast. That stuff is horrendously expensive. I seem to remember paying around $10.00 a pound for nickel alloy stick welding rod, and that was several years ago. By the time you factor in labor time and materials cost, it won't take long to make a rehabbed drum impractical, at least in a large majority of situations.
Jerry

Spraying gets decent bonding to non dirty casting which I’m assuming the drum is
Spray welding a brake drum is a known process
Just no one does it anymore
There were some restoration shops that did super rare drums for 1910s20s era vehicles

I’m just thinking about how to do it for cheap at home
The bond doesn’t need to be super great
The material added is under shear, the original drum will take the hoop stress.

Anyway I’m not gonna be messing with this process until I’ve exhausted all machine shops in my neck of the woods
Fitting a liner is also an option but machining that is a big delicate project too
-Stan

I'm very familiar with spray welding. My father's fellow racers built up crankshaft journals that way to make 4 1/4" stroker crankshafts for flathead Ford round track cars back in the early 1950's. Personally, I wouldn't bet my life on a brake drum repaired that way, nor put others on the road around me in that kind of danger. Racers choose to take the risks involved in their sport. The soccer mom with the minivan full of kids who happens to be ahead of you at a stop sign when a brake drum fails might not be as willing to take that kind of a chance.
Jerry