Installing New Brakes - Dragging and jammed

B

BVZ24

Member
I severely needed new brakes and have been trying to replace them this spring. I'm working on the car more or less alone and I don't have any contact info for anyone who does brakes in my local chapter. I ordered the brakes as a set from a vendor and replaced all 4 backing plates, with the included cast drums. All rods are detached including the parking brake. This morning I thought I was ready to adjust and attach the rods, but when I back off the adjusters, even as far as they go, the brakes still contact the drum and drag on it. No free spinning at any point. Furthermore, when I tested the actuators by hand, my driver front brake jammed and won't release. The actuator is currently resting slightly rear past vertical and the wheel still can be spun barely, so I bet that backing plate has to come back off.

I'm 27 and inherited the car. I had no real instruction on how to do any of this other than the occasional mention of "The engine's bad" and "He spent a lot of money on those (original) shocks". I came to the conclusion that the brakes were bad on my own, from the scored stamped drums, the adjusters going from free spin to nearly locked in one click, and thin shoes. I got it driving, I rebuilt the engine, but with these brakes, my budget and optimism are nearly gone. And I'm not quite sure how these "lot of money" original shocks work, but I don't think they're supposed to flop around with no resistance. But I need the brakes first.
 
Stuck brake - I tapped the axle pin with a hammer and it unstuck. I still need to find out why, because it can't happen again stopped at a stop sign.
 
Put your general location in your profile. It may pay off for you in ways you don't expect. Call the vendor and ask if the brake shoes were arced to the drums, if not, that could be your problem. They may have been the expectation that you would have them arced. Who did you buy the brakes from, the vendor may have a bad reputation and that could be the problem. Did you check them out in the archives? Keep going, it will be fun once you get the initial problems worked out.

Charlie Stephens
 
There’s a video on YouTube about brakes but I can’t think of the title, someone will be along who does remember. Watch it
 
Good Morning...Look up Paul Shinn videos or Model A Basics...You might/should find helpful information...Ernie in Arizona
 
The drums are going to not be concentric to the bearings when they are first installed on the hubs. Have they been machined to make them concentric?

The shoes will bed-in when the car is run for 20 miles or more. They should stop dragging then. But the shoes need to be concentric with the bearings too. There are little tracks that the heads of the pins that the rollers ride on that determine the position of the shoes and these tracks should be an accurate position from the bearings and they should be flat. Tools to check for concentricity are sold by the vendors but you can get a good idea by the distance from the surface of the shoes to the edge of the backing plate. That should be the same all the way around. The heads for the pins for the rollers is a larger diameter than the ones for the adjustment pins on the other end. Do not mix them up.

Both adjusting pins should be the same length on each wheel and have a sharp end where they seat against the adjusters. The should have the correct angle.

The shoes should be fully retracted with the arm forward. The shoes should move out correctly with no binding. With the slack taken up the arms in the front need to be 15 degrees forward and further movement aft of the arms should start the shoes moving out. Use the "pills" and/or new pins (the ones that go through the king pins) to make the angle correct.

Check to see if the shoes match the drums by placing the shoes in the drums with the drums on the ground or bench.

There is much more. Your best bet is publish your town and find someone who has experience with Model A brakes. The brakes are probably the most important part of your car. Get some expert help even if you have to pay for it.
 
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Found it,,,, https://youtu.be/i8f7VlKQnhQ?feature=shared Watch this,,,. Paul Shinn has awesome how to videos as well. It takes a bit to get your head around model A brakes or at least it did for me. I welded my tracks and filed them by hand not really having a clue what I was doing but it luckily turned out ok for me. Watch and listen to all advice you can get and eventually you’ll be telling others what to do for theirs. Good luck with it!!!!
 
Ring Mike's before you start modifying anything. Good advice from nkaminar #8 as always. As he says once you get them in the drums and turning a bit "he shoes will bed-in when the car is run for 20 miles or more" . Check everything again with rods disconnected and drums off,( I suspect wedges-not sitting correctly or a fraction oversize, or springs in wrong holes -or lining a smidgin too thick, but suspect you've checked those already :) ) tap the shoes lightly and work the lever to get them settled. Sometimes chamfering the leading edge of the lining is needed ( this can be done with a file in situ). Use of a stick of blackboard chalk on the lining can show up where there's rubbing.
 
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BVZ24,
You might have a problem with the brake an actuating pin sticking within the spindle bolt . Either because of worn spindle bolt/kin pins or a bind somewhere that prevents the pin from moving freely. It could also be over travel causing it to get stuck . I give the brake seminars for Marc at the national meets and know them well. As I read your note I’m glad as a young guy you are doing this but sense your frustration . There is nothing easy about A brakes, especially when it doesn’t go right.
You can drop me a line at Marctech@ modelarestorers.org with your phone number. Happy to chat on this issue for you. Better than back and forth on forum.
Larry Shepard
 
I forgot to mention to check to see if the rollers are seating correctly on the wedges in the front and the cams in the back. The cams in the back should move freely in the camshaft.
 
I was able to move the actuating pin freely if the arrowhead shaped wedge is held down.

I'll check the rollers this weekend.
 
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