1946-1948 Brake Shoe Position
 

I have read opposing information for shoe position on the Lockheed brakes. Fortunately there are only two choices.
I had not seen a diagram before today but found one on VanPelts website.
According to the drawing (and some folks Ive read inform that) the primary shoe (front) is the long one and the secondary (back) is the short one.
the other opposing option is the reverse shoe placement.

Can someone help explain the Lockheed shoe movement / reaction. The bottom of the shoes are fixed and rely on more pressure to press into the drum. The larger half of the wheel cylinder is forward.....does the rear shoe move first.....

Checking fit: The 51a-2028 brake cams I have are cad plated steel. They insert over the pin and the shoe fits over the cam without excess play. (I found these to have the correct play, the gap was hidden by the copper kote).

Re: 1946-1948 Brake Shoe Position
 

With LOCKHEED brakes, the LONG lining and the LARGER BORE on cylinder BOTH go toward the FRONT. This of course, is opposite of the shoe placement on Bendix "self-energizing" brakes where the LONG lining always goes to the REAR.


Coop

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Re: 1946-1948 Brake Shoe Position
 

Thanks Coop- I got it reversed in my dialog, the drawing correctly shows the orientation.
I’m looking for perfection. Im using new drums arched shoes and feel the braking could be better. It may take a few miles for the shoes to seat in.

Re: 1946-1948 Brake Shoe Position
 

That's true, that the linings and drum surfaces may need to 'season' themselves. You say NEW drums, and that the shoes are arced to the drums. Would you care to elaborate a little on what the NEW drums are, where you got 'em, and WHO did the arcing for you since that service is so hard to find now-a-days? Ya know, there's a reason that many folks are changing over to the Boling Brothers' Bendix-type brakes, especially with the fronts.

Coop

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Re: 1946-1948 Brake Shoe Position
 

I like the Boling Bros drums. The drum can be turned to .090, are notably heavier, and made in USA. I could not afford to invest in the Bendix backing plates at this time so I bought the drums thru Cornhuskers (Krylon) and used 39-41 hubs, on 46-48 backing plates.
Since the drums are new while Rochester Clutch and Brake had my shoes I had them arch them too. I used a soft woven lining which was recommended to work well with the Lockheed system.
The 46-48 drums I removed were within spec but the 1980s shoes with a hard lining were not making uniform contact with the drums. The New setup is a vast improvement but I feel it could be better. I need to investigate the cams tomorrow they may not be a correct fit to allow the shoes to float..... checked the cams and they are OK- going to put a bit more driving time on the new setup. Having drums that slide off of the hubs is a nice feature.
While the technical aspect of 46-48 brake adjustment is simple I do not have the feel for finding the sweet spot on these yet. Still learning - - -

Re: 1946-1948 Brake Shoe Position
 

A final comment to post #5.
The tip I received to adjust the brakes so that the drag is enough to stop the wheel within one rotation when spun by hand worked for me. While subjective in nature it gives a measure to apply to ones adjustment technique.

The assembly I crafted to use 37 pedals with a 39-48 master cylinder did not work. The pedal ratio was adversely affected and full pedal pressure could not be achieved.
Using 39 pedals that gave a direct in line travel to the MC solved the soft brake pedal. The brakes come on fully with nominal pressure at about 1/3 pedal depression.
With the New Boling Bros drums on 39 hubs and a soft woven lining and the afore mentioned 39 pedals the brakes work very-very well. I won’t go back to a hard lining on these early brake systems, they were designed for soft lining. The woven material may wear a little sooner but a small price to pay for great brakes.
Added features: the ability now to service the brakes without removing the hubs & the design of the Boling Bros drums should yield to a stronger brake action will less fade due to heat.

Re: 1946-1948 Brake Shoe Position
 

REALLY appreciate the update! Glad that this has seemingly worked-out well for you.

Coop

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Re: 1946-1948 Brake Shoe Position
 

Yup Coop,
It stops so well I’m a gonna put a hand hold in for the passenger to hold onto.
Or maybe I should just slow down ...............naw, hand holds sound better.
Have a great day.

Re: 1946-1948 Brake Shoe Position
 

All great info. Where did you get the soft woven linings if you don’t mind. ThAnks.

Re: 1946-1948 Brake Shoe Position
 

A EFV8 mechanic friend recommended Rochester Clutch and Brake in Victor NY.
If you give them your specs they will come arched.

Sam @ 585-924-3717

Re: 1946-1948 Brake Shoe Position
 

Re: 1946-1948 Brake Shoe Position
 

Did you have to send them cores?

Re: 1946-1948 Brake Shoe Position
 

Yes - I stripped & cleaned them beforehand to be sure I had picked 8 good shoes.
T.