1947 brake drum
 

I bought new drums from MAC's the spindle mounts to the outside, I have a chunk of change in these things at this point with having the hubs switched over, and a few other challenges with what should have been a pretty straight forward easy job.
The drum will not fit over the new brake pads, yes, the adjustment cams are in, the brake cylinder does not appear to be pushing out the shoes, small shoe installed forward drums have been turned.
Has anyone else bought these drums and have experience with them?
Help, lol!

Re: 1948 brake drum
 

Get a brake drum micrometer, or take your drums to a machine shop.
The drum may be machined to a smaller size than 12.000 inches.
OR your shoe linings maybe too thick. There is the possibility that
(if the shoes are new, read- made in China) the webbing could be made incorrectly.

Just in case, I would put a drum into place on the car WITHOUT the shoes
to check for other issues- before machining the drums to 12 inches.

Karl

Re: 1948 brake drum
 

The drum is just right at the point of going on, by a hair.

Re: 1948 brake drum
 

Sounds like a problem I had. The drums were NOS and the shoes didn't fit. I found out from the place that supplied the shoes that they arced all shoes for a 12.030 drum. Not being able to find a place to arc the shoes I returned them to where I bought them and they returned them to the manufacturer to be arced correctly. When they came back everything went together fine.

Charlie Stephens

Re: 1948 brake drum
 

Typically the shoes need to be arched to match the drums. I'm not sure who does that type of work in Wichita.

Re: 1948 brake drum
 

I know an outfit that does it, I've never had new brake parts in an assembly as basic as this be such an expensive sob to get back together,.

Re: 1948 brake drum
 

That's Lockheed brakes, I'm not a fan. Bendix is a piece of cake by comparison IMO. Because of the way Bendix brake shoes can float around they somewhat fit themselves to the drums. With the Lockheed shoes being pinned in one location they need to be matched to the drums.

Re: 1948 brake drum
 

I would think that when these cars were put together, they stuck new shoes on them and popped the drum on, I really wouldn't think they would be getting carried away shaping the shoe to a drum, its going to shape too the drum in the first twenty miles of driving.
The shoes do not look over large, the drum is "12 across, I put a strap around it and squeezed it down and opened the bleeder valve to see if the shoes would move In a little, it was a no go.

Re: 1948 brake drum
 

The drum wall is a solid eighth of an inch, should I have the drums turned down further.

Re: 1948 brake drum
 

Again, I'm not a Lockheed fan or expert, but from what I understand the shoes would always need to be fit to the drum. They may have had fixtures that trimmed to shoes so they would fit on the first assembly. With all new parts it is much easier to accomplish. No idea really. Lots of task that seem difficult now were simple and quick on the assembly line. :)

Re: 1948 brake drum
 

Lockheed brakes only expand from the top. Bendix move and expand two ways for better braking action. They are sometimes referred to as double acting brakes. There is a process for adjusting Lockheeds. I would not make a new drum larger than 12-inches. The shoes would go first before I would do that. The drums are only good out to 12.060" so don't prematurely wear out a high dollar part. Either get the shoes arced or send them back.

Re: 1948 brake drum
 

I will take the shoes in and have them taken down, I'm close to just using a belt sander on the things.
Everything I read says the EPA shut down brake shoe arcing machines.

Re: 1947 brake drum
 

An easy way to measure the drums is with a precision 12 inch ruler and a feeler gauge. Similar problems convinced me to spend the extra money on bendix brakes and drum lugs designed for modern press in lugs. The extra $1,000 was worth it IMHO as no more lockheed troubles.

Re: 1947 brake drum
 

This may not solve your problem, but as I recall, the short lining goes to the rear on Lockheed brakes.

Re: 1948 brake drum
 

I think you need to reread it. The EPA required the machines to be modified so that dust did not excape from the arcing. The modifications and associated paperwork were so expensive that most of the machines were scrapped.

Charlie Stephens

Re: 1947 brake drum
 

If they are really close to going on sanding or filing a slight bevel on the leading edge of the linings may get you there. You can also remove the shoes and put some psa sand paper on the inside of the drum and do a home-brew arc job.

Re: 1947 brake drum
 

I had close to 5000 miles on the brake shoes on my Model A with 40 Ford brakes. The drums were getting thin so I got new drums from Sacramento Vintage Ford. They would go on if clocked right but would not turn. They were out of round big time. As I recall it took almost an eighth to get them round. Yes, the shoes were adjusted as far back as possible. The bottom line is that many if not most repro drums are out of round and need to be turned to make them right.

Re: 1947 brake drum
 

I used a belt sander and got the drive side on, it seems like a cheesy way to do them but the one outfit in town that seems to do older stuff really hasn't impressed me much with their workmanship. Slightly frustrating, for the amount of cash I have in the front brakes at this point.
I had the drum turned when the hub was switched over.

Re: 1947 brake drum
 

After some more googling it does appear you are right ford up until 48 has the primary shoe forward which is backwards from most other drum brakes.
Does that sound right to the experts here, big shoe forward?

Re: 1947 brake drum
 

big shoe to the front, and big wheel cyl piston to the front. backwards from self energizing modern brakes. i like your get er done attitude