Left rear brake drum gets hot

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Moparmadness408

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On my 1967 plymouth valiant, Im experiancing issues with the brakes. I did an 8-3/4 swap and put the 11 inch shoes on the rear. They seemed to work great until I had to swap out the third member due to noisy gears. At first I thought I may have over adjusted that side, but it turns out it’s adjusted fine. The drum comes right off, and has very minor drag on it. The springs, shoes, and wheel cylinders and drums are all new. The car developes that overheating brake smell, and the left rear drum gets to 250 degrees while the right reaches 80 degrees. The fronts are discs and run around 140 degrees. This is on a 35 degree day. If the drums aren’t over adjusted, what would cause just one side to run hot?
 
bad bearing? dragging shoes...i'd bet its a spring issue.
 
Almost looks like the 80 degree one isn't working fully and placing the stress on the other side. Might look to the parking brake cables and all the associated parts to see if it hanging up.
 
Check the temp of the bearing area after running for a while.
 
Post #3 is spot on. Rather than look for a reason why the left is working too much, look for a reason why the right is not working. Might have air in it.
 
Agreed, it's not that the left side is working too much, it's that the right side isn't working much if at all. Make sure you didn't run the U-bolt on that side over the brake line. I've seen that happen with the same result. Anything plugging the line can do it too.
 
cudamark said:
Agreed, it's not that the left side is working too much, it's that the right side isn't working much if at all. Make sure you didn't run the U-bolt on that side over the brake line. I've seen that happen with the same result. Anything plugging the line can do it too.
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You know what I found once? It was on a Volkswagen Beetle. This was probably about 1981 and in the high school auto shop. The other two shop classes had all taken a swing at it and struck out. So, Mr. Lovett came to me and asked if I would look at it. He knew I was sharp on brakes, as even though I was a kid, I had been in the work force since I was nine. I started a simple trace of fluid pressure. Why the other classes hadn't done that I have no clue. Within 20 minutes I had it isolated to the very left rear wheel cylinder where the brake line screwed in. There was a small ROCK blocking the fluid passage in the wheel cylinder. So unbelievable, but that's what it was. Just crazy.
 
Ok, so I got to looking at it, and found the parking brake mechanism works correctly. With the shoes off, it moves freely and the lever that is connected to the cable returns to it’s original position. Both rear wheels don’t turn when you hit the brakes. I went to go reinstall them and discovered that left rear drum has some serious taper right at the end. You can’t quite get the drum to set all the way on the hub. When you put the wheel on, and tighten the lug nuts, the drum wedges itself on. I swapped the drums around, and sure enough, now the right side gets really hot. So Ill get the drum resurfaced and let you guys know.
 
What rear axle did you use? Do the shoes match the backing plate? 2 1/2" shoes on 2" backing plates might cause that too.
 
I have the same issue. Had the car out the Sunday before for a 1/2 hour jaunt. Pulled in the garage and smelled something hot. Sure enough, the left rear wheel is rather warm. I've changed nothing to affect this, all worked fine for years after the swap. Moser axles w/green bearings and I have 11 x 2" drum brakes. Haven't had a chance to look at it yet, possibly this weekend. I'll post what I find.
 
So I resurfaced that drum, and it was really warped for only having 600 miles on it. I reinstalled it, and they both got to 150 or so in the rear. I didn’t drive it real far, a few miles or so. The fronts were showing 75 degrees. I adjusted the proportioning valve to were it has less pressure. Today I drove it, and now the left rear drum is getting up to 245 while the right rear reads 80. They’re both adjusted to where they need to be. Both rear brakes engage when you hit the pedal, and release once you let off. I turned the proportioning valve almost all the way in, and am letting the brakes cool down.
 
cudamark said:
What rear axle did you use? Do the shoes match the backing plate? 2 1/2" shoes on 2" backing plates might cause that too.
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So the guy who built the rear diff has configured the brakes. It appears the shoes are 2.5 inches wide, and how do you tell it has all the right parts? It has an 8.75 inch rear diff
 
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Do you know what your real axle assembly came from? Custom made? A stock A-body 8 3/4 would have 10 X 1 3/4" brakes. If yours has the big bolt pattern and 11" brakes, there are 3 different backing plate possibilities. 11 X 2, 11 X 2 1/2, and 11 X 3. Each one uses different shoe hold-down pins, shoes, and drums. All the parts need to be for the same size shoes, and match the backing plate. You should be able to tell if there is a mismatch because the shoe friction surface won't be square with the backing plate. A 2" shoe on a 3" backing plate will be at an angle were the outer friction surface of the shoe will hit the drum when applied, whereas the inner surface (next to the backing plate) won't hit the drum.....at least not until lots of uneven wear happens. Other shoe/backing plate mismatches will result in the same type problems, sometimes reversed where the inner will hit and outer won't. There are a few combos that can't happen.....such as 3" shoes on a 2" backing plate. You just can't get the drum seated against the axle flange in that case. The easiest way to make sure is to use a framing square against the backing plate and shoes to see if they're sitting straight and square. I've seen a few drums that weren't cut correctly for the shoe it's made for, causing the edge of the shoe to rub on the vertical surface of the drum. It's a similar situation if you use a 3" brake shoe on a 2 1/2" backing plate/drum combo. Along with a cocked shoe problem, the shoe bottoms out in the drum and hits a section of drum that hasn't been machined.
 
cudamark said:
Do you know what your real axle assembly came from? Custom made? A stock A-body 8 3/4 would have 10 X 1 3/4" brakes. If yours has the big bolt pattern and 11" brakes, there are 3 different backing plate possibilities. 11 X 2, 11 X 2 1/2, and 11 X 3. Each one uses different shoe hold-down pins, shoes, and drums. All the parts need to be for the same size shoes, and match the backing plate. You should be able to tell if there is a mismatch because the shoe friction surface won't be square with the backing plate. A 2" shoe on a 3" backing plate will be at an angle were the outer friction surface of the shoe will hit the drum when applied, whereas the inner surface (next to the backing plate) won't hit the drum.....at least not until lots of uneven wear happens. Other shoe/backing plate mismatches will result in the same type problems, sometimes reversed where the inner will hit and outer won't. There are a few combos that can't happen.....such as 3" shoes on a 2" backing plate. You just can't get the drum seated against the axle flange in that case. The easiest way to make sure is to use a framing square against the backing plate and shoes to see if they're sitting straight and square. I've seen a few drums that weren't cut correctly for the shoe it's made for, causing the edge of the shoe to rub on the vertical surface of the drum. It's a similar situation if you use a 3" brake shoe on a 2 1/2" backing plate/drum combo. Along with a cocked shoe problem, the shoe bottoms out in the drum and hits a section of drum that hasn't been machined.
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It’s from a dodge truck I believe and the axle tubes were cut to the right length for an a body. The drums are 11 inches in diameter.
 
Depending on the year, most Dodge pickups with an 8 3/4 had 11 X 2" brakes. There were some '72-4 models with 11 X 2 1/2" however. What do your shoes measure?
 
Ok so I went through and checked the shoes against the backing plate with a straight edge. And it seems to be sitting straight on the backing plate so I don’t suspect a mismatch of parts. I also tested to see whether the front or rear brakes lock up first and the rear brakes don’t actually lock up at all. So at this point I figured it has to be something in the wheel. I swapped the brake shoes around, inspected each spring, even did the drop test, and found no problems there. I assembled everything and drove it. Now the left rear gets up to 407 degrees, and the right rear 286. You could smell the brakes overheating badly. The left front rotor was at 86 degrees and right front at 140 degrees. So it seems like I may have an intermittent issue causing both rear brakes to get hot, and also a consistent issue with the left rear brake running hotter.
 
I took it for a drive, and the left rear wheel was starting to lock up. It turns out the pin that holds the adjuster lever fell out and damaged the drum and the shoes. So Im getting new shoes and a drum, and you guys said pictures help, so here you go. Tell me if you see something not right. Oh yeah, and I did swap the shoes around to where the small one is facing towards the front, and the big one facing towards the rear. But everything else is the same.

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Stupid question what are new parts and what are origional? Talking shoes and drums. New shoes eat the OEM drums some worse than other Craig would know @mobileparts Just and idea. Also are the drums cut to the same diameter and the shoes arched to them?
 
can't tell from pics. Do you have the Left adjuster on the Left (driver's side) backing plate? The Left adjuster has an "L" stamped in rhe end of the adjusting screw, and the kerf of the adjuster's "buttress" teeth should face downward so that when the pawl moves upward it will grab a tooth, but when the pawl returns to its starting position it will skate across the backside of the tooth easily. Have you tried advancing the adjuster pawl by hand? You can simulate actual operation by plucking the apply cable sideways. The pawl should grab one tooth at a time, then after one "pluck" should return back into its starting position ready to grab the next tooth.
 
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