Emergency Brake not working

[Southbronco1]

Hello friends, I have a 1970 bronco with standard suspension, no lift. The emergency brake always seemed somewhat insufficient to me, but since lowering the axle to replace the leaf springs, it no longer works at all. I suspect that I stretched the cable when lowering the axle. I removed the drums to inspect it, and can see that the cable does actuate the brake about an inch or so, but doesn’t appear that it’s actually pushing the brake shoes out in any material way. Everything seems tight from the floor pedal all the way back to the actual break, with no apparent slack. I can’t see any way to adjust the cable, but am I missing something? Is there anything I can do inside the brake assembly? I should mention that my regular brakes are properly adjusted and working very nicely. Any advice would be greatly appreciated.

 

[thegreatjustino]

You can adjust the tension on the cables by tightening or loosening the nut on the adjusting bracket underneath the Bronco. Where the single cable from the pedal splits into two cables to the rear drums. Adjust the tension both ways to see if it helps. Cheap (free) and easy place to start.

 

[B RON CO]

Hi, how far down does the parking brake pedal go? Post a picture of the rear brake assembly so we can see if the brakes are assembled correctly. Good luck

 

[Steve83]

The adjustment is at the equalizer. But if it's already slack-free, that's probably not a solution. Post pics.

This is pretty cluttered, but if you go to the NEXT 3x, that diagram is easier to unnerstan:

(click this text)


The last 4 on this page show the e-brake linkage:

(click this text)

 

[DirtDonk]

Also, how are you gauging whether or not it works?
I know that sounds like a silly question, but are you testing it by trying to stop the rolling vehicle? Or are you using it as a parking brake on a hill and it’s not holding?
If on a hill, is it not holding the vehicle from going backwards, or forward? The difference being the self energizing aspect of the shoes.
If you’re trying to stop the rolling bronco, how big are your tires, and how big are your brakes?
Do you have the 10 inch brakes, or 11 inch brakes?
These may not have anything to do with your actual problem, but they are good data points for us to know.

 

[Southbronco1]

Also, how are you gauging whether or not it works?
I know that sounds like a silly question, but are you testing it by trying to stop the rolling vehicle? Or are you using it as a parking brake on a hill and it’s not holding?
If on a hill, is it not holding the vehicle from going backwards, or forward? The difference being the self energizing aspect of the shoes.
If you’re trying to stop the rolling bronco, how big are your tires, and how big are your brakes?
Do you have the 10 inch brakes, or 11 inch brakes?
These may not have anything to do with your actual problem, but they are good data points for us to know.

Finally circling back on this. Thank you for your responses. @DirtDonk, I'm running 30" X 9.5" BF Goodrich all terrain tires on 15" wheels. I have 10" drums/brakes. I'm not trying to stop the vehicle while rolling, but just trying to park it on a hill and not worry. I have only tested it facing down hill I believe. Didn't occur to me to try it both ways, but I will. I did try adjusting the tension at the splitter (tightened and loosened all the way) to no avail. I'm attaching pictures of the brake assembly. I'm including a clockwise image selection of the assembly so you can see if it is assembled correctly. I included the last two pictures so that you can see how far the e-brake bracket is being pulled by the cable. The first of those pictures shows the e-brake disengaged, and the very last picture shows it with the e-brake engaged. YOu can see that it probably isnt moving enough. I scratched a marked on the backing plate to see if the brake pad moved out at all, and it had not. Thanks for any thoughts. Hoping to not have to install all new cables, but maybe so. Steve

 

[Oldtimer]

Looking at first photo, brake cables need to go below leaf springs.
Yours appear to be over top of frame.

 

[DirtDonk]

Yep, need to disconnect them up at the front and reroute them under the springs.
Or get some really long ones!.
Yours are pretty sprung tight in the pictures, so even though that’s not necessarily how they would sit when you’re on the ground, they’re not acting normally no matter what.
When you’re pushing the pedal right now, it’s fighting you.

But I see something else as well I think.
Does it look to you like both shoe’s friction material are the same length?
They both look like short shoes from here.
You should check the other side to see if they are both long.

On properly working drum brakes, or for them to work properly I should say, the front facing shoe is always shorter than the rear facing shoe. This encourages their “self energizing“ function. That’s what I was referring to with my directional comments previously.
And while I don’t know this next thing for a fact, I would think that it could greatly affect the holding power of the parking brake.

Lots of cheap imported shoes don’t have different length friction surfaces anymore. They also make them too thick sometimes so they don’t even fit in the drum.
This is the world we live in.

 

[Southbronco1]

@DirtDonk and @Oldtimer , thank you both for this feedback. I had no idea they were supposed to run below the springs. It explains a lot, because when I bought the truck, it had the old suspension on it, which I eventually replaced. Prior to replacing the suspension the E-brake barely worked, and after putting in the new springs, it doesn’t work at all, which makes sense with the springs being stiffer, and an even greater distance for the cable to get over to the break. I’m going to reroute them this weekend! Thanks again so much for your help.

PS you are correct in that my brake pads are the same length on both sides, so, if rerouting, the cable doesn’t make a difference, I will replace those with the correct smaller pads on the front side.

 

[Southbronco1]

@DirtDonk, @Oldtimer, circling back on this. I re-routed the cables to run below the leaf springs, and still no measurable improvement. I'm going to order new cables and see if that will change anything. Before I do, I wanted to better understand exactly how the e-brake works. I can see where it pulls at the bottom of the link bar, which appears to pull the top part of the bracket towards the front of the car and in doing so pushes the spreader bar in the same direction which forces the front part of the shoe out towards the drum. That sound correct? If so, I'm not understanding the purpose of the spreader bar spring. I'm assuming that it plays some role in sending the spreader bar back to its original place when the e-brake is released, but i cant see how that happens because the springs doesn't appear to be connected to anything other than the spreader bar. Its just looks like its sitting there wrapped around the spreader bar. Any thing you can do to illuminate my understanding of this is greatly appreciated!!! thanks as always

 

[DirtDonk]

I always assumed that the simple function of the spring was to reduce rattling, and to ensure that the spreader bar stayed in place when the shoes were moving around.
Especially under conditions when the shoes might have come out of adjustment and could move farther than expected when the brakes were applied.
It may certainly have other functions, but I really never paid much attention to it.
So I’m as much interested as you, to hear from those that have more detailed working knowledge of brakes.

 

[DirtDonk]

And don’t buy new cables until you’re certain you need them. If yours are frozen up, you certainly need them!
If the cables are pulling and moving the brakes accordingly, then I wouldn’t think you’d need new cables.
Perhaps they’re stretching? Or perhaps they are resisting movement of the parking brake pedal. But you can tell that by testing before buying new ones.

 

[DirtDonk]

Actually, now that I think about it, it’s possible that the positioning that they had over the springs before, has actually created a kink or a failure point in the cables inside.
In that case you wouldn’t necessarily be able to see them, and might have to do some special testing to discover that.
At some point new cables are warranted, I’m sure, but the original cables are really well built as long as they’re in good condition.

 

[Southbronco1]

Actually, now that I think about it, it’s possible that the positioning that they had over the springs before, has actually created a kink or a failure point in the cables inside.
In that case you wouldn’t necessarily be able to see them, and might have to do some special testing to discover that.
At some point new cables are warranted, I’m sure, but the original cables are really well built as long as they’re in good condition.

Thank you. Previously, they were entering at a steep angle, so indeed may have gotten a kink.

 

[Oldtimer]

I also thought they were anti rattle springs.
IT pushes the spreader away from front shoe, and against rear shoe.

Another area to check is the drivers floor, and fire wall.
When I apply parking brake, there are rips in floor and firewall sheetmetal where parking brake bracket is bolted.

I also had to replace the cable bracket (next to fuel tank selector valve) when it came loose from the floor pan.

 

[Steve83]

...I'm not understanding the purpose of the spreader bar spring.

I always assumed that the simple function of the spring was to reduce rattling, and to ensure that the spreader bar stayed in place when the shoes were moving around.

I also thought they were anti rattle springs.

Zactegly. The function of the drum brakes' various operations are explained on this & the NEXT several pages (in agonizing detail):

(click this text)

 

[DirtDonk]

When you say, agonizing detail, I’m almost afraid to dive in. But I’m far too curious so I’m going to anyway! Thanks for posting the link. Hopefully it loads reasonably quickly this time.

 

[Speedrdr]

Zactegly. The function of the drum brakes' various operations are explained on this & the NEXT several pages (in agonizing detail):

(click this text)

Great freaking agonizing detail indeed! I didn’t make it all the way through but have learned a bunch. Thanks, @Steve83, for linking this data. Will def read it through to the end when I start working the emergency brake.

Randy

 

[Southbronco1]

@Steve83 thank you for this!!!