I recently bought a 1949 Chevy 3600. I admittedly have limited automotive knowledge, but decided to teach myself. The truck had been sitting for years. The drums took a lot of convincing to get off, I used a lot of penetrating oil to get the two flathead screws loose. We decided to replace the wheel cylinders, huck brakes and brake springs on the front. I put everything back together, one side works fine, the other not so much. I have the wheel cylinder pistons fully retracted, the drum slides on easily, and spins easily, until i put in the 2 flathead screws. Once those are in the drum won't spin at all or will with significant drag. I rechecked my assembly which looked correct. I tried switching the drums from one side to the other thinking this would help me d32cide if the drum needed to be turned down. The problem persisted on the same wheel.
Someone I asked suggested that the new shoes maybe misshapen or the wrong size and that is the problem. Measuring the thickness they seem right. Does anyone have thoughts? Did I put it together wrong? Should i have the drums turned down? Any help is appreciated.
I would start by laving the drums off, and putting the 2 flat head screws in. Then make sure the hub still turns freely. If so, then the interference is the drums. Then put the drums on and slowly tighten the flat head screws while rotating the drum, to see when it binds and hopefully rub marks will tell you what is hitting.
The other thought is that 70 year old trucks have had a lot of repairs through the years. Originally It would have had Huck brakes, but did someone change them over at some point? And make sure you put the correct replacement parts in, a lot of chain auto parts stores do not "know" the parts, they just give you what the computer says fits, which isn't always correct.
When I have the drums off the '51 (3600) I always adjust the brakes a bit before reinstalling the drums. If I've gone a bit too far with the adjustment the same thing happens when the two screws are tightened. Drums won't turn. The solution has always been back to the shoes off a bit.
Now the above is assuming all's right with everything as Jon covered.
Try bolting the wheel on without installing the screws and see if the drum locks up that way. If it does, you've got a problem with the drum or the assembly of the brake. If the wheel spins OK with the screws gone, the screws are probably too long and they're binding on something behind them. Also check to see if the drum is dragging on the backing plate with the screws tightened. You might have bent the backing plate while trying to remove the stuck drum. Jerry
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I want to second the advice not to turn the drums. Those are probably the only drums you will ever see for your truck. I would try installing the drum with four of the wheel nuts turned so the the flat side faces the drum.
Those linings should have a slight bevel at the top edge of the shoe. You can see that in all the Huck diagrams in the shop manual. I would create that with a file.
Thanks for all the ideas. I took a closer look and found that the top of the new wheel cylinder was rubbing on the drum. Small amount of filing and now the wheel spins freely. Thanks again for the help, I am sure I will be posting more questions as I continue my work.
