Emergency Brakes Binding

E

ebrand57

Junior Member
Hi, I am assembling my 1930 Sport Coup following an off the frame body repair (rust galore).

Background: My father bought this car about 1960 and completely redid the brakes, new shoes, emergency back plates, etc. The car has been used off and on for the past 54 years as a back road jalopy (and probably only been driven about 300 miles in that time). The past few years I had been having problems with the right rear emergency brake grabbing, which eventually resulted in that backing plate being very mangled. I bought a new one with the plan to install it when the body went back on...ie now. I removed the old back plate and installed the new one (reaming the toggle bushing, etc), and putting on the new toggle lever spring (thanks to previous threads for making that task not too bad). When I tried to hookup the emergency brake level actuating rod, I had some positioning problems (could not get the levers aligned to put the two pins in, so I investigated the left emergency brake mechanism (previously untouched and working fine). I found that the left toggle had limited rotation and was sloppy. I disassembled the left side and found the toggle bushing/toggle shaft to be a problem...tried to disassemble, and bent the back plate....so ordered a new plate (and toggle). So, now I had two new back plates with good fitting bushings.

The brakes shoes appeared to be in good condition and I attempted to reuse. When I went to install the drum on the left side, I found that the drum was binding on the emergency brake shoe even with the toggle released (to ensure the shoe was fully retracted). I checked the shoe and it is sitting uniformly on the back plate. The drum appears to be in good condition. I lightly sanded both ( in case of the odd burr), but had the same result, the drum was severely binding even with the toggle fully released.

I turned my attention back to the right side, and essentially found the same problem...worse, I cannot even get the drum over the fully retracted emergency shoe, tried the same thing...sanding, looking for high points, etc...nada.

So to summarize: All parts are the same (and were functioning...absent the right occasional lockup with mangled back plate), except for two new backing plates . Both right and left shoes appear to be in good condition and the drums appears to be good.

Something is not the right dimensions, or not "round", both back plates are new, and bought almost two years apart, the shoes are from the brake job 50 years ago, and had fit ok, the drums are unchanged. I measured the shoe lining/metal band and found 0.30 inches thick uniformly. Since the only thing I replaced is the back plates, I conclude that the dimensions of the new replacement back plates are slightly larger than what was installed 50 years ago.

So, my questions:

Is the brake shoe/bank thickness ok (0.30 inches), or is this too thick?

Could the brakes drums (not sure if replacements of 50 years ago, or new...suspect much older as they have some scoring in the service brake area...and we have never worn the brakes that much in 50 years) be slightly smaller than spec.?

Are the replacement back plate dimensions slightly off? (I found no complaints about this on the forum).

Any suggestions are appreciated!

Ethan Brand
Roscommon, MI
 
Ethan

I just measured the brake lining and band on mine and it's just the same as yours 0.300
My emerg. brake carrier measures exactly 9 inches in diameter. I think it was Bratton's who stopped selling the carriers for now because they found that the repop's were to big. Maybe that is what you purchased. I'm sure all the vendors get theirs from the same supplier.
I would try to locate originals. Try Bert's in Denver, Colorado. Hope this helps.
 
Hi, thanks for the quick reply. I bought from Snyders, so I will call tomorrow to see if they have some problems, offer any solutions. I will measure the news ones and compare to the old. Perhaps I can grind the new ones down?
 
Ethan, I was also having a problem with my rear brakes and could not get the drum on. One thing I found was the adjusting wedge on the service brake was not retracted all the way, and this was causing the brake shoes to contact the drum.Try removing the emergency brake shoes and see if the drum slide on. Ed Saniewski
 
HI Ed

Thanks for the reply. I did remove both sets of emergency brake shoes and had no binding from the service brakes (and I had previously backed off the service brakes to ease drum installation as a matter of course from previous drum brake experience)
 
Update. I just called Snyders. They were very helpful. Bottom line is that this problem is likely a confluence of slightly thicker replacement lining than original, and ongoing fit problems with the back carrier. Solution is a combination of peening over the tabs on the carrier to 90 degrees, and taking a belt sander to the lining to thin it a bit. The design clearance between the lining and the drum (with the toggle fully relaxed) is apparently very small (10-20 mils?) so it is easy to end up with parts that won't initially fit together.
 
Ethan
I wouldn't reduce the lining thickness. The bending of the tabs might help as they might be expanding the bands. My linings are the same thickness as yours and fit perfect.
 
Ethan

Before you do anything else, check to see if the ebands are on the correct way. There is an inner and outer edge. If not correctly put on, they will be on an angle on the carrier and not allow the drum to seat properly. The best way to check is to look at the side or the assembled emergency set-up and compare the edge of the band to the carrier. They should have the same spacing all the way around. Approx 1/4 to 3/8" Hope that this helps!

If not, then give me a call as I do a lot of backing plate rebuilds and sell a lot of cast iron brake drums including assembled on hubs.

Randy Gross
melmodela@aol.com
714-292-8660
 
Randy this thread is from 2014... it was brought back to life from post #8 replying to a spammer that was deleted . either way you did post good info for others
 
Hi

Thanks for the recent posts (not sure what brought this thread back to life?), the additional information is very helpful. The car is back on the (back) roads and driven with loads of kids and wistful adults (my Grandfather had a Model A, Thank You so much, etc...lots of smiles). No issues with the emergency brakes since I followed Snyders advise and did some "field" fitting.

On a completely separate, but amusing issue:

After my adhoc off frame repairs, (including a ****** partial), the car would make a really annoying buzzing/rattling noise in a certain rpm range. Spent hours trying track down the source...which seemed to originate in or near the bell housing. I thought the worse and was grudgingly preparing to do some major rework. The other day I was again trying to find the source...with success! Long story short: I had taken out the unusable glass windshield (the car is not licensed at this time) and put in a "temporary" plexiglass replacement. You guessed it...with no really bedding or seal. The noise was the plexiglass vibrating in the frame a certain rpms! After winter storage I will bed the temporary windshield with silicone. I'll replace with a real windshield once I decide to put a plate on it...which is dependent upon replacing the 60 year old Allstate tires once my allowance is replenished :).

Best wishes to all.

Ethan Brand
 
A good windshield man in Canada told me years ago to not use silicone around windshields, as silicone on the metal promotes rust. He said to use a good windshield urethane.

Ever walk through a junk yard and see the amount of rust around windshields where someone smeared a bunch of silicone? Now I know why.
 
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