Rear brakes

J

jlking2010

Member
I recently bought a '31 Victoria and after inspecting the brakes, determined they needed some work. I have welded up the tracks, replaced the rollers and pins, replaced the cam, cam shaft and cam shaft bearings, replaced the adjusting wedge and adjusting pins. I also put new cast iron drums on. I did not replace the shoes as they looked fine to me. My issue is related to the first step in adjusting the brakes. I have turned the adjusting wedge all the way in and still no drag when turning the wheel. Seems with almost all new parts, I should get some drag long before fully rotating the adjusting wedge. Any help is appreciated. Jeff
 
Any pictures of the brake assembly with the drum removed would help.
There are at least a few possible causes for this problem.
 
There is a “stop on a dime” video that is very good. You must have something big wrong, but it should be easy to find.
 
it could be problems with the brake rod and service brake cross shaft set up . In other words if the rear brake levers aren't being pulled all the way, you won't be getting full activation . As for the rear adjustment wedges , The square end needs to be backed out as far as it will go , when installing the brake drums . After the drums are installed , the square end of the adjustment wedges will need to be screwed-turned inward until brake drag can be felt . Then back off as needed to remove excess drag . I would make these adjustments with the service rods disconnected at the rear brake levers. You only need to remove the brake rod clevis pin. . You can check your work by pulling forward on the rear brake lever . If you can get this far , come back and we can get into brake rod and shaft setup .
 
To the OP, are you saying front brakes or rear brakes? Or both? If it's the rear brakes, check your operating wedge isn't turned 180 degrees in the wrong direction.
 
The problem is, I turn the edge in all the way with no drag. Don't think the rods have anything to do with this problem.
 
Probably means the rear brake cam . If the brake adjusting shafts that connects to the brake shoes are reversed a person probably wouldn't be able to get the drums on .
 
Refer to the diagram. Your issue most likely is in the mechanical path starting at the adjusting wedge, adjusting shafts, brake pin, pins holes and drum.


The operating cam is not in the line of action causing the problem.


I realize that you have replaced rear brake parts with new ones, but which ones did you replace? Consider these causal factors:

  • Adjusting wedge conical surface is worn. This necessitates the wedge to go in further;
  • Adjusting shafts are worn. The wedge end of the shafts have a blunt point that rides on the adjusting wedge. The blunt point wears requiring the adjusting wedge to go in further;
  • The pins connecting the shafts with the shoes wear, and so do the pin holes in the shaft and brake shoes. The adjusting wedge would go-in further to take up this wear;
  • Brake lining thickness affects the amount of travel of the adjusting wedge. There are woven linings and molded linings. Originally, the woven lining material was 0.172" to 0.182" thick, and the molded linings were 0.162" to 0.172" thick. Wear makes them thinner, especially on the molded linings which wear faster;
  • The wall thickness of the brake drum also has an affect on the travel of the adjusting wedge. Original 11" diameter drums had a wall thickness of 0.140". Cutting the inside diameter reduces the wall thickness and causes the adjusting wedge to go in further;
  • A rare occurrence, but check it anyhow! Is the adjusting wedge housing loose?
  • Another possibility is wear of the wheel bearing / bearing journals which allow the brake drum center to rise. The axle housing journal wears on its bottom from 5 to 7 o'clock. The same wear occurs in the brake drum journal;
  • A loose backing plate also allows the brake drum center to run-out.
 

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Do you know if the adjuster worked before? Is there a chance someone ground the adjuster rods down too much in the past?
 
All waiting to help. I'll add just one comment: The shoes that are being reused would have an arc to correspond with the old and replaced drums. The new iron drums will be a smaller diameter. When shoes or drums are replaced, the shoes must be fit to the drums with a brake shoe grinding machine.
 
I lied. Try taking off a front drum. same system. Turn the adjuster and watch what happens. Pull the actuating lever and watch what happens. Remember, rods pull toward center of vehicle to actuate.
 
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