OK. I’m out of ideas – truly appreciate any help / insight / ideas y’all might have! Short version – I can’t get my front drums on the car with correct brake shoes. 1929 roadster with 1940(ish) drum juice brakes all around including two 10 lb residual valves (one front, one rear), “speed bleeders”, and using DOT 4. Tore front brakes apart when I first got the car and found the top chunk of the shoe material had been removed on the front wheel’s shoes. Didn’t register as a red flag at the time, though it should have. Later, I replaced the shoes and drums wouldn’t go on the car. No matter how I adjusted them the top of the shoes hit the drums. I made a temporary fix by shortening the metal tab on the shoes that go into the wheel cylinders (let’s call these “temporary shoes”). Started working on finding the real problem… - Had the drums resurfaced to ensure they are round - New shoes – arch matches the drum perfectly when laid inside them - New front wheel cylinders / cups / springs /etc (1" x 1-3/8" bore) - New brake return springs (in case the old ones were tired) - Replaced the flex line between the backing plates and hard line (to ensure no line collapse issue) - Master was a disc/drum master and was always engaged by +1/8” so replaced master cylinder with ’67 Mustang drum/drum model (bench bled, believe 1” bore) and ensured 1/16” free play between the pushrod and the piston for master cylinder - Added a master cylinder return spring - When I open a bleeder valve, have always got a little squirt of fluid – consistent with 10lbs of pressure held in lines The two 10 lb residual valves aren’t needed at this point – but they shouldn’t be causing any issues. Any replacement parts have come from Van Pelts – great resource. I found a cool little jig that lets me “see” what is going on without the drum on the car. Confirms the backing plate is centered but the shoes stick out too far on the upper portion of the shoes. Pictures attached (with the “temporary shoes”). I’ve read every post I can find. Have a couple books on juice brake conversion. I’ve adjusted the brakes every way possible and in only the most extreme position can I begin to get the drums on using the temporary shoes– leaving no room for wear / adjustment. Thanks for reaching this much – appreciate your questions and any thoughts!
I bought some repro shoes from Carpenter about five years ago and found the lower holes were not in the proper place. I had to sand extra friction material off the shoe to get the drum on. I also found the steel material was too thick and needed grinding to thin it so the lower pivot tie bar wouldn’t clamp tight on them when the nuts were tightened. Has worked fine since, after I went through all work to fix them.
If you open the bleeders and push in on the shoes do they move inward? Just wondering if the 10 lb. valve is holding too much. How about removing the 4 mounting bolts so the backing plate is free to float.Would the drum go on then? You might hunt up a pair of Original shoes,and check hole locations.
I can see that it looks like the upper adjusters are backed off all of the way and lower eccentrics are lined up dot to dot like they should for initial installation. The lower adjusters with the dots move the shoes up and down so if I was in your position I would see if lowering the shoes down would help get everything centered, as already mentioned there has been issues with the lower hole in the shoe web not being in the right place on the aftermarket parts. If you can't get everything ***embled with playing with the eccentrics, then the for sure way to go would be a set of relined OEM shoes. I had the source for them at the top of my head and it just vanished from my brain matter. If I remember I will edit this comment.
"I made a temporary fix by shortening the metal tab on the shoes that go into the wheel cylinders" So that is a common, "NEEDS TO BE DONE" on the aftermarket shoes. Some of the sets I've been sent have a little instruction sheet that tell you to do this in them I would consider that as needed and not a temporary fix these days.
If you have a set of old shoe cores, I can highly recommend Brake Warehouse in Minneapolis area as expert reliners. They will arc them to the spec you need for each individual drum. Then they will work perfectly.
I agree it sounds like the lower anchors are set too high. Loosen the lock nuts and rotate the center bolt and watch the shoes move up and down.
Thanks for the feedback everyone! @alchemy and @Hitchhiker - I didn't realize the changing the shoes would be OK / normal. I'll be able to adapt them a little more and should work great. @jaracer / @BJR / @Pocket Nick - I've adjusted the shoes every which way. Even when eccentrics are pushed down as far as possible, was still having the same issue with the tops of the shoes not fitting in the drums. Thanks again!!!
I'm going to say something is wrong with the shoes, were they touch the wheel cylinder. If you had an old (70s or under) shoe to measure against that would tell. You could try different shoes or set all adjusters at zero, grind a little at a time as test fitting, so you can still have some adjustment left. Look at the difference in distance from wheel cylinder to friction material or backing.
Update: I finally got hands on an original set of brake shoes. The anchor holes on the new reprod ones are nearly 3/8" lower than original (effectively pushing the whole shoe up). Thanks for all the ideas and feedback!
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