Hey guys, Im about 90% done with a juice brake conversion and ran into an issue of my drums rubbing on what I believe to be the shoes. Only on the rear drums. Its a stock A rear, with clings modified backing plates, and new shoes, wheel cyl, etc as well as the shim on the tapered part of the axle. I can still spin the drum but its just not as free as I would like it to be before I start adjusting them. The shoes are in the fully collapsed position, Im trying to upload a video showing how it spins (or doesnt spin) too freely. I have attached some pictures of the backing plates and shoes and where its rubbing, as well as a picture of the car sitting on its new wheels haha Any ideas on what i could do to fix it?
All older Car's & Truck's have Chanferd Brake Shoes Could the be your Problem mabey I am not saying Right but the Front & Back of the Shoe Should be on a Angle to the main Body of it . Hope This Helps, Just my 3.5 cents Live Learn & Die a Fool
I almost forgot Maker Sure the Drums are Not out of Round if the Drum's were Droped or Stored wrong it can make get out of Round.! Just my 3.5 cents Live Learn & Die a Fool
I had this same problem last summer with my Model A/'39 brakes. The culprit was the new shoes that most vendors are selling these days. Had to grind the outer metal edge of the shoe. Also, sometimes you have to use more than one axel shim (not ideal, I know). FYI, while I was at it I also arced the shoes as best I could (meaning fitted them to the drum) using a body file and feeler gauges. And chamfered the leading edge of the linings. All of this was SOP back in the day.
As long as things aren't grossly out of whack, the high spots on the shoes will wear in and match the drums. It used to be standard practice after new shoes to go for a ride and "bed" the brakes.
correct me if I'm wrong but it looks like the area that is rubbing is just the face of the shoe (the wear surface). If so and like you said the adjustments are all the way in, can you just run them and they will wear in? From your photos, they look like the non-adjustable bottom anchor style, the later model of this style brake. If these were the older style you could adjust the bottom anchors to move the shoe down and get it more centered in the drum. As it is, I would just run it to were them in and readjust as needed. I say all of this thinking that the only problem is the area where I see that the drum inner surface was contacting the shoe wear surface. When adjusting these drum brakes, you should have some drag.
Rumor has it the new shoes have longer than original tabs ( the part that goes in the wheel cyl ) I guess it was to accommodate larger than spec drums . Check against an old set od 40s shoes if you have .
First off, the axle taper looks to be quite rough. If you lap the axle taper to the hub the axles will live a lot longer. Be sure to tighten the nut to 200 ft. lb. If you arc grind the shoes to fit the drum, the rub problem will very likely go away. Any brake shop can do this. While you are at it, you might consider a set of safety clips. They are cheap and this is the time to install them.
Looking at the pictures, looks like your brake shoes are not arced to match the drums. Cars these days use disk brakes so brake shoe arcing is becoming a lost art. You might have to call around to find someone that still arcs shoes.
Here another issue with these new shoes: Sometimes the tab that fits into the wheel cylander is too long and needs to be filed down. Since you are having difficulty getting the drum to spin with the shoes totall collapsed, that could be your issue. Backed all the way in, the shoes are still too far out, even before you adjust them. Your shoes appear to be the same manufacturer as mine. I bought several sets from two differenet vendors. The second vendor at least had the decency to inform me of the possible issues I might encounter. They were: 1) tab for wheel cylander might be too long, and 2) the material in the lower portion of the shoe might be too thick (i.e. the metal surrounding the lower adjuster holes). Also, the wear pattern on your shoes definitely indicates they should be arced to the drum. You are making contact at the outer edges, not in the middle. Mine where the same. I corrected this with a body file and feeler gauges (see pic below). I explain it on my speedster build thread; scroll down to post #865: https://www.jalopyjournal.com/forum...out-of-the-weeds—build-thread.1003005/page-29 This reminds me I'm overdue to update my thread on the difficulty I had with the rears shoes. Frankly, by the time I was done I was so fed up with Lockheed brakes that I needed a break myself.
I took a file to the very top edge of the shoes and with only a few minutes of filing, the drum spins freely now... I'm not too sure about how the arc of the shoes fits against the drum, but would it be wrong to just adjust the brakes until I get contact and then bleed the brakes and then run the car like it is until the shoes match the drum? I just have a banger in there and wont be able to go over 50 for the most part... but if I just drive it around my block at 25-30 for a 50-100 miles, wouldn't the shoes just match the drum from use? The drums themselves have been turned what I believe to be 0.060" so theyre slightly oversize. The drum does spin freely with no noise, while the shoes are fully collapsed, but I want to know if my thinking is slightly hokey or if it'd be safe enough to just drive it around taking it easy? Thanks! Gordy
Well, you've sort of done a crude arc. Might be enough. You should chamfer the leading edges while you're at it. Very easy to do. Lots of guys do it the way you describe; get them adjusted until they feel good and drive them, hoping they'll wear in. Seems to works for some, but when I tried it didn't work for me. (Of course I had other contributing factors.) If that's your plan, I urge you to "bed them in" and then do a few trial panic stops in a nice safe place, to see how the brakes react when working together. Doesn't have to be a crazy speed, but it should be a hard stop, like as if a deer jumped out in front of you. Also try it on a dirt or gravel road; you can look at the skid marks to see if all brakes are grabbing more or less equallly. In my case, the right front wheel would lock, and none of the others. The car would pivot on that wheel, whipping the tail into the oncoming lane of traffic. I just couldn't continue driving my car in that condition while the shoes seated themselves.
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