Rear brakes (both sides) dragging BAD

[jeffncs]

All new everything from the pedal to the brake cylinder. The pass side rear drum brake drags so bad that it melted the axle a bearing on that side…. I can post pics tomorrow but shoes and springs are “right”. No clue on which rear but it was 11” brakes on it.

I'm seriously thinking about ripping the drums off to install a rear disc kit with the e-brake. Please save me $600 and offer some ideas…

1977 D44 with stock disc setup. Rear 9 with drums.

Could it be the wrong distribution block?

Having taken it apart like 5 times…it’s almost as though the shoe gets stuck / wedged outside the shoe guide which locks it onto the drum.

 

[dmoses42]

Steve83 has a good diagram on where the things inside the drum need to be lubricated, that could be an issue. Does the shoe and drum look like they are rubbing on each other when they are turning? Might be the shoes are the wrong width and binding up. Or a bad wheel cylinder right out of the box. I wouldn't think the distribution block would cause it only on one side. Actually Steve83 has tons of good info on 9" drum brakes in general.

 

[Torkman66]

I also do not think this is the distro box. Some questions: did this start exactly after you replaced all the brake components or did it drive fine for a time then this happened? What does the drum look like…scared, warped? This may not be brake issue at all. Depending on your answers, this could be a bearing that seized in axle and nothing to do with brakes. Let us know. Pics are good too. I would not jump into disc brakes. Drums are easy system and work great. We can get this fixed!

 

[B RON CO]

Hi, If you can post a picture of the brakes it might help. Make sure the parking brake cables are not frozen. Good luck

 

[Oldtimer]

The "shoe guide" surfaces on my backing plates were worn deep enough I had to build them up with welder, and grind smooth.
Also, take a look at hydraulic piston on that side. It may be binding and not retracting.

 

[Broncobowsher]

I could see a bad hardware kit causing excessive self adjusting brakes.

Do you just back off the self adjuster and they are good? What is the fix between this repeating?

Do you use the parking brake? Is that what is hanging up?

 

[SLOWnEASY]

The self adjusters are side specific. Have you checked they are on the the correct sides? Now that I think about it that probably causes the brakes to loosen not tighten. But it's worth a check. And yes a picture or two of the rear brakes from a few different angles might help.

 

[Broncobowsher]

Correct on self adjuster on the wrong side. It will loosen the brakes as it should be tightening them. That is mixing the LH and RH threads in the self adjuster and what side they go on. Friend fought this in high school. Every weekend he was redoing the rear brakes as the self adjusters were all the way in. Finally figured it out and swapped the adjusters to the correct side and all was good.

 

[jeffncs]

Thanks for all of the great ideas and suggestions. I’ve gotten so frustrated with these brakes that i took a few weeks off to get my Mustang project off the ground.

I’ll get some pics tomorrow.

I’ve had this problem since “go”. This rear came without backing plates or drums. There just axles stuck in the tubes for tires to roll on.

I found backing plates in the stash that fit which had drums available. 1 drum is new, 1 drum was turned (he did say it wasn’t true on the outside but was able the turn it enough so the interior was round.

Local parts place supplied me with the hardware kit, shoes and brake solenoid.

First test drive around the block resulted in screaming hot drums. I immediately pulled both tires and found I had reversed the shoes. I was rushing and just wasn’t thinking when I threw it together.

I corrected the shoes, adjusted things and thought I was good to go. Drivers side seemed fine. Pass side started dragging and heating up. I messed around with that side some more and thought I had it dialed in.

Local car show benefit came up and I decided to follow wife driving her Bronco and made it ~1.5 miles before I smelled the rear brakes burning (dragging). I turned into our neighborhood and the pass side bearing started squealing. I’m guessing I melted the seal.

I made it home and parked it away from the other vehicles and house just in case the brakes somehow started a fire.

 

[El Kabong]

The "shoe guide" surfaces on my backing plates were worn deep enough I had to build them up with welder, and grind smooth.

Those surfaces are what I was thinking too.

I've seen the flat spots where the shoes slide on the backing plate worn to the point where when the shoes expand they get hung up on those little nubs, keeping them engaged. The outer edges were sort of stair stepped.

Mine was years ago on a 56 F100. My guess was that those points hadn't been lubed properly for many years. Elusive problem. Removing the drums can pull the shoes out enough to free themselves from the bad nubs, hiding the issue. My dad, a 50s hot rodder, turned mechanic, turned auto shop teacher, pointed me in the right direction. He was a pro on drum brakes. Once found you could sure feel the wear with your finger.

Same fix. Built up material on the nubs then ground smooth.

 

[jeffncs]

Those nubs may be the issue. Last time I pulled it apart, the shoe was stuck on that. I may try before getting too crazy.

Thanks again! I’ll get some pics tomorrow and check out the nubs.

 

[Broncobowsher]

One used drum, one new drum. Only one side has issues.
Move the drum to the other side. Maybe it is flexing, cranking up the adjuster and causing drag. If the problem moves when you swap drums side to side, it is a bad drum.
It is a free check. Not firing the parts cannon at it. A little time and a test drive is all it takes. Nail it or rule it out.

 

[jeffncs]

Hi all!

I’ve been wrapped up with family stuff and took a break from the Bronco to work on the Mustang. I’m back at the rear brakes now.

I’ll include pics below. Here are my observations.

Passenger side - Significantly more shoe wear - note the dust on the shoes and on brake hardware. All new parts with only short test drives.

Passenger side bearing turns free with no notable play, binding or other oddities. Pass bearing movement comparable to the driver side bearing. Bearings are also new.

Both sides observed to have the shoes in correct place; drums were easily removed unlike previous assessments with the drums were stuck due to displaced drum shoes.

Rear differential fluid (also fresh) smells and looks good. Clear almond color; no burnt smell.

Will clean up the brake hardware, shoes and drums, reinstall axles, swap the drums as a reset then test drive to see if anything changes.

 

[El Kabong]

While you've got that open, I'd sure be checking for wear on these nubs:

 

[Steve83]

Something is wrong on both sides because the secondary (front) shoe doesn't touch the anchor pin. That alone can "energize" the brakes, so I'm surprised both weren't dragging.

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And I don't see any brake grease.

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[jeffncs]

Something is wrong on both sides because the secondary (front) shoe doesn't touch the anchor pin. That alone can "energize" the brakes, so I'm surprised both weren't dragging.

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And I don't see any brake grease.

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Test drive complete. Both are dragging. My IR temp gun went off the chart for both drums.

Based on my heat issues, that brake grease is likely long gone.

Both clearly dragging.

 

[jeffncs]

Here are pics and observations…

Both drums were could / stuck on due to the shoes not sitting back into their “home locations”.

Took pics of the center, front and rear shoes. Not sure if it’s the tabs or crappy brake cylinder seats not retracting.

Compared to my wife’s rear brakes, something not “resetting on mine and I just can’t figure it out.

 

[Broncobowsher]

You are on the right path. The top of the shoes need to rest on the anchor pin.
Try cracking the bleeders loose, do the shoes retract at that point? Could be an issue with the flex line failing and acting like a check valve, or even the master cylinder not uncovering the transfer slop properly and relieving the pressure in the brakes.

 

[ksagis]

What Broncobowsher x2 in that a failed hose can totally cause brakes to not release and a super easy check. But you said you changed all parts from pedal to drum?

Edit, if the transfer port wasn't uncovering, is doing a gravity bleed a good check? i.e. if you open a bleeder and there isn't a constant dribble with the MC going down, then there's an issue?

 

[EPB72]

I'd be looking at the parking brake ,,, first is there some slak in the cables ? or not returning all the way check where all three connect .
but before that check the spreader park link bar that goes across between the shoes atrest there should be about 1/8-3/16 inch play .. I'm suspecting the parking brake lever on the rear shoe is not returning to its rest position ,, ..