‘48 Rear Drums

[JSeery]

There were two type of brake systems used, the first were Lockheed. These were later replaced by Bendix. They are very different in the way they function. In very basic terms, the Lockheed brake shoes are held in place with a pivot at the bottom, the Bendix "float" at the bottom. Bendix brake are what you would be familiar with on modern drum brake cars. The attached photos ae Lockheed style brakes.

[JSeery]

From another Ford site:

"LOCKHEED ‘39 THROUGH ’48 FORDS AND MERCS: These brakes were designed and manufactured by Lockheed. Hydraulic pressure expands the wheel cylinder cups, which push the shoes against the drum. The shoes are NOT self-energizing. The Lockheed system is a front/rear shoe design with the bottom pivot for each shoe anchored to the backing plate. This design requires more pedal pressure to stop than self-energizing brakes since they rely solely on hydraulic pressure. The front shoes (primary) do most of the stopping and normally use a longer friction band. The rear shoes (secondary) normally use a shorter friction band."

"‘39-’48 LINCOLNS AND ’49-’53 FORD/MERC: These are designed and manufactured by the Bendix Corp. They are self energizing (often referred to as duo servo) brakes. The self energizing is caused by the two shoes being linked to each other at the bottom, but are NOT attached to the backing plate (like the Lockheed design is). The top of the primary shoe is moved outward by hydraulic pressure from the wheel cylinder to contact the drum. The rotation of the drum “wedges” the floating primary shoe to move it downward. Since the bottom of the two shoes are not anchored to the backing plate, this rotation movement is transmitted through the rear most shoe where it forces the shoe against the drum. This increases braking substantially and decreases brake pedal effort. This results in considerably more braking force than the sheer hydraulic pressure design used in the earlier Lockheed brakes. The primary of a Bendix system is still the front shoe in all wheels... just like the Lockheed brakes are. However since the Bendix is self-energizing, the rear (secondary) shoe applies much more stopping than the front (primary) shoe does. The secondary shoe now has the longer friction band and the primary now has the shorter friction band."

[V8COOPMAN]

Originally Posted by Otterby

Thanks! Those drums from MT look nice! $135 for a drum is still nuts but I’m fine paying that if it’s a quality product. Does anyone know what modern press in studs I should use with my original inside hubs and the Lincoln style drum?

Originally Posted by Otterby

Has anyone used these drums from speedway? I'm curious how they compare to the Boling Bros. drums? What does Bendix style mean? I have 12" juice brakes with inside mounted hubs.

https://www.speedwaymotors.com/12-x-...akes,5847.html

Otterby.........You keep mentioning "INSIDE MOUNTED" rear hubs for your '48. '48 Fords came equipped with hubs mounted on the outside of the drum. '46-'48 drum/hub assemblies have a big flange staring you in the face, with the drum mounted from the rear. IF your drums are mounted from the rear like '48 should be, I'm pretty sure the MT replacement drums will NOT fit those hubs. The MT drums work great on the '40-'41 hubs, after making the proper provisions with the aftermarket wheel studs outlined above.

BENDIX--style is what the more modern type of drum/shoe brakes (like the MTs) are called. The shoes are not rigidly mounted to the backing plates....they're allowed to float. The stock old Ford brakes have the shoes mounted to a pivot at the bottom of the backing plate. These are called LOCKHEED-style brakes, and are NOT self-energizing. DD

[Otterby]

Thanks for the information. Attached are pictures of my drum/hub and rear brake assembly. It is an inside the drum mounted hub. Most places do show that it should be an outside mounted hub those years but I have seen a few places that do show an inside mounted hub available in '48. It does have the Columbia rear if that makes any difference. It's clear to me now that I do not have Bendix brakes so I am assuming the Speedway drums will not work. Every measurement was the same with the Speedway drums except the overall diameter. Mine is approx. 13.37" and the Speedway drum is 13.63".

So, there are no dimensions on the Boling Bros. website. Is there drum the same size as the one from Speedway or is it the correct size for my setup?

[V8COOPMAN]

Originally Posted by V8COOPMAN

Otterby.........You keep mentioning "INSIDE MOUNTED" rear hubs for your '48. '48 Fords came equipped with hubs mounted on the outside of the drum. '46-'48 drum/hub assemblies have a big flange staring you in the face, with the drum mounted from the rear. IF your drums are mounted from the rear like '48 should be, I'm pretty sure the MT replacement drums will NOT fit those hubs. The MT drums work great on the '40-'41 hubs, after making the proper provisions with the aftermarket wheel studs outlined above.
DD

Otterby.....Below are two examples of what '46-'48 rear drums/hubs should look like. Note that the hub is mounted OUTSIDE the brake drum. If you look at the INSIDE pic, it becomes apparent why the replacement drums won't fit these hubs. Hope this helps a bit. DD

[Krylon32]

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I would spend the extra money for the MT drums. USA made and true. I used to sell the Speedway drums before I got a MT dealership and had customers complain they had problems balancing their tires? Never experienced it myself but I had a friend who used the Speedway drums and they destroyed his brake shoes. They seem to be extra hard?

[V8COOPMAN]

Originally Posted by Otterby

Thanks for the information. Attached are pictures of my drum/hub and rear brake assembly. It is an inside the drum mounted hub. Most places do show that it should be an outside mounted hub those years but I have seen a few places that do show an inside mounted hub available in '48. It does have the Columbia rear if that makes any difference. It's clear to me now that I do not have Bendix brakes so I am assuming the Speedway drums will not work. Every measurement was the same with the Speedway drums except the overall diameter. Mine is approx. 13.37" and the Speedway drum is 13.63".

So, there are no dimensions on the Boling Bros. website. Is there drum the same size as the one from Speedway or is it the correct size for my setup?

Otterby.....It's your lucky day!! Those drums/hubs that you pictured are the early ('40-'41) style. They work every bit as well as the '46-'48, and the IMPORTANT dimensions (like lining-up with brake shoes and fitting axle properly) are identical.

The brake drums we're talking about are ALL considered to be 12" drums. Brake drums are measured across the drum from one shoe surface to the other shoe surface.....INSIDE the drum! Re-measure yours, and you will probably end-up with 12.0??", or even larger by a few thousandths.

The brake drum does not know the difference between Lockheed style and Bendix style brakes. The drum just provides an internal, flat surface for the shoes to rub against.

The "LUCKY" part about your day is that you need those early "INSIDE THE DRUM" hubs to fit the MT replacement drums. I've heard that the Speedway drums are produced "offshore". I also have first-hand experience with the MT American-made parts. I'd stick with the MT stuff. Boling Bros. is the way to go. Their drum IS the right size. It is 12.000" measured inside, across the center.

Does this further help ya understand about these old brakes? More questions.......ask away! DD

[JSeery]

Originally Posted by V8COOPMAN

Otterby..... The brake drum does not know the difference between Lockheed style and Bendix style brakes. The drum just provides an internal, flat surface for the shoes to rub against.

The "LUCKY" part about your day is that you need those early "INSIDE THE DRUM" hubs to fit the MT replacement drums. DD

That's what I thought as well, but I am just not familiar enough with Lockheed brakes to be make recommendations on drum interchangeability! Looks like DD has you on the correct path!

[V8COOPMAN]

By the way, the brake shoes on this left, rear of the car are mounted on the backing plate BACKWARDS. With LOCKHEED brakes (which we now know they are), the shoe with the long lining goes toward the front of the vehicle. The large part of the wheel cylinder also goes toward the front, which this one does, correctly. DD

[Ggmac]

I think that's the gas tank to the right , making the left the front . I think ?

[V8COOPMAN]

Originally Posted by Ggmac

I think that's the gas tank to the right , making the left the front . I think ?

Correct.....which makes this the left (driver side), rear brake (obvious) on the car. The REAR shoe (long lining) should be mounted toward the front, which it ain't in this pic. DD

[Otterby]

Originally Posted by V8COOPMAN

Correct.....which makes this the left (driver side), rear brake (obvious) on the car. The REAR shoe (long lining) should be mounted toward the front, which it ain't in this pic. DD

I'll have to double check tonight but I'm positive my service manual showed the short lined shoe towards the front? I didn't question it because that's the way the old ones were installed. I really appreciate you pointing that out if you think they're wrong though!

[Mart]

I always just remember "Big Big" for the early ford brakes big lining and big end of the cylinder go towards the front. This goes for any wheel, front or rear.

Where the confusion sometimes comes from is that later self energising (Bendix style) brakes normally have the shorter shoe to the front.

But for early Fords, Big Big is the rule.

Mart.

[Otterby]

Here is the diagram I used from the manual. I obviously need to pay closer attention. I assumed this was for the left side by the way the squiggly underline is under "ASS'Y LEFT". However, now that I look at the parking brake hardware and how the brake cable enters the backing plate it's clear the diagram is of the right side. Thanks for catching that!

[Mart]

I can see where the confusion can stem from. If you're going to show the front and rear brakes on the right side, at least put the rear to the left of the front. (Front of car is on the right of the pic).

Lot of good info in the pic, though.

Mart.

[George/Maine]

The ford drums I don't think they are marked with 12.060 max.
I think to cut larger started after 1948
There is all most 3/4" of meat on the drums.
Throwing good drums away when they could be turned to 12 .150,
I would really like to see a egg shaped 1948 drum.
If you have a chance to die take it.

[JSeery]

I don't have an earlier Ford Service Manual in front of me, but the 49 - 52 manual states to not bore the drums past the recommended limits. The limits are listed under brake specifications and appear fairly standard, example for F1 is 11.060.

[19Fordy]

FYI: Here's what the MT Products Boling Bros. 12 in. drums look like. They are worth the money. Plus, you no longer have to use a wheel puller to remove the drums.

[Pete F]

It kills me when I see prices at of around $100.00 for a brake drum.
I have been in the business for 50 years and the prices we pay for drums is a rip off just because we are driving classic cars, the same drums for normal cars are a fraction of the cost


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[Otterby]

Originally Posted by Pete F

It kills me when I see prices at of around $100.00 for a brake drum.
I have been in the business for 50 years and the prices we pay for drums is a rip off just because we are driving classic cars, the same drums for normal cars are a fraction of the cost


Sent from my iPhone using Tapatalk

I don't get it either. With shipping, just two drums will be close to $300. It's crazy how much more some things cost. I do need rear drums though and am going to get the Boling Bros. drums. It's pretty clear that they're a quality product and I agree that the brakes are nothing to get cheap on. I was able to turn the front drums and they now measure out at around 12.020 so I'm comfortable with that.