A Cars forum. AutoBanter

If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below.

Go Back   Home » AutoBanter forum » Auto newsgroups » Technology
Site Map Home Register Authors List Search Today's Posts Mark Forums Read Web Partners

Drum brakes - do you disconnect the parking brake cable?



 
 
Thread Tools Display Modes
  #1  
Old January 8th 18, 08:02 AM posted to alt.home.repair,rec.autos.tech
Mad Roger
external usenet poster
 
Posts: 57
Default Drum brakes - do you disconnect the parking brake cable?

I haven't done drum brakes ever but I'm faced with these drum brakes where
I'd just like to ask a couple of questions from those of you who have done
drum brakes before.

1. I released the parking brake from the cabin and screwed these 2-inch
long metric 8mm x 1.25mm threads bolts to pull the drum off the shoes.
<http://www.bild.me/bild.php?file=5687240drum_brakes_0.jpg>

2. After blowing the dust out (and not breathing it in), I could see that
the front shoe was worn down to about a millimeter or less (after 175K
miles), so I'm going to have to buy new shoes and replace them.
<http://www.bild.me/bild.php?file=3478506drum_brakes_1.jpg>

3. I measured the drum to be 2mm smaller than the maximum diameter:
<http://www.bild.me/bild.php?file=9335528drum_brakes_2.jpg>

4. Where the maximum diameter of 297mm was stamped on the drum itself:
<http://www.bild.me/bild.php?file=9428041drum_brakes_3.jpg>

5. It was hard to get the drum back on even with the parking brake released
from the cabin, so I had to use a mallet to bang it back on:
<http://www.bild.me/bild.php?file=2434045drum_brakes_4.jpg>

The main question is whether I'm supposed to *disconnect* the cable for the
parking brake when working on the drums, and particularly when I put the
new shoes on after I buy them.

Also, only one shoe is worn, and it's the front shoe, and it's been on
there for 175K miles, but I wonder if the shoes can be switched, so that
the front shoe is in the rear and the rear shoe is in the front, since they
wore so unevenly (sort of like rotating tires).

But mainly I'm not sure what the procedure is for the parking brake cable.
Can you advise?
  #2  
Old January 8th 18, 11:28 AM posted to rec.autos.tech
dsi1[_11_]
external usenet poster
 
Posts: 269
Default Drum brakes - do you disconnect the parking brake cable?

On Sunday, January 7, 2018 at 9:02:24 PM UTC-10, Mad Roger wrote:
> I haven't done drum brakes ever but I'm faced with these drum brakes where
> I'd just like to ask a couple of questions from those of you who have done
> drum brakes before.
>
> 1. I released the parking brake from the cabin and screwed these 2-inch
> long metric 8mm x 1.25mm threads bolts to pull the drum off the shoes.
> <http://www.bild.me/bild.php?file=5687240drum_brakes_0.jpg>
>
> 2. After blowing the dust out (and not breathing it in), I could see that
> the front shoe was worn down to about a millimeter or less (after 175K
> miles), so I'm going to have to buy new shoes and replace them.
> <http://www.bild.me/bild.php?file=3478506drum_brakes_1.jpg>
>
> 3. I measured the drum to be 2mm smaller than the maximum diameter:
> <http://www.bild.me/bild.php?file=9335528drum_brakes_2.jpg>
>
> 4. Where the maximum diameter of 297mm was stamped on the drum itself:
> <http://www.bild.me/bild.php?file=9428041drum_brakes_3.jpg>
>
> 5. It was hard to get the drum back on even with the parking brake released
> from the cabin, so I had to use a mallet to bang it back on:
> <http://www.bild.me/bild.php?file=2434045drum_brakes_4.jpg>
>
> The main question is whether I'm supposed to *disconnect* the cable for the
> parking brake when working on the drums, and particularly when I put the
> new shoes on after I buy them.
>
> Also, only one shoe is worn, and it's the front shoe, and it's been on
> there for 175K miles, but I wonder if the shoes can be switched, so that
> the front shoe is in the rear and the rear shoe is in the front, since they
> wore so unevenly (sort of like rotating tires).
>
> But mainly I'm not sure what the procedure is for the parking brake cable..
> Can you advise?


It depends on the cable. Some have a spring that keeps the cable end firmly in place. Those can be tough to put back on. In that case, I'd leave the cable attached. The parking brake arm is held on with a clip so you really don't have to detach it. Just clip it on the new shoe with the cable attached.

Your photos don't show any spring attached so it could just fall off when you detach the arm from the shoe. Make sure you take a lot of pictures. I was working on some brakes a couple of weeks ago and just blanked out on where to attach a spring. Your brake looks pretty simple so that's a good thing..

It's normal to have one shoe worn more than the other - they were designed that way. Brake shoes are cheap, so replace both. A hardware kit with new clips and springs are nice if you can get it. Good luck!

  #3  
Old January 8th 18, 01:03 PM posted to alt.home.repair,rec.autos.tech
Meanie[_3_]
external usenet poster
 
Posts: 2
Default Drum brakes - do you disconnect the parking brake cable?

On 1/8/2018 2:02 AM, Mad Roger wrote:
> I haven't done drum brakes ever but I'm faced with these drum brakes where
> I'd just like to ask a couple of questions from those of you who have done
> drum brakes before.
>
> 1. I released the parking brake from the cabin and screwed these 2-inch
> long metric 8mm x 1.25mm threads bolts to pull the drum off the shoes.
> <http://www.bild.me/bild.php?file=5687240drum_brakes_0.jpg>
>
> 2. After blowing the dust out (and not breathing it in), I could see that
> the front shoe was worn down to about a millimeter or less (after 175K
> miles), so I'm going to have to buy new shoes and replace them.
> <http://www.bild.me/bild.php?file=3478506drum_brakes_1.jpg>


It appears the one shoe is unevenly worn. Could be a bad cylinder or
another stuck part such as the adjuster. Check them and replace/repair
if needed.
>
> 3. I measured the drum to be 2mm smaller than the maximum diameter:
> <http://www.bild.me/bild.php?file=9335528drum_brakes_2.jpg>


Maximum diameter of what? Are you aware of the adjusters? Each side has
one and it sits under the cylinder behind the hub. You can see it in
this diagram
http://repairguide.autozone.com/znet...5280089c12.gif

It's job is to keep the shoes against the drum and is automatically
adjusted when the parking brake is used. Often, this is the reason why
drums are difficult to remove. They are adjusted from the other side
through an opening using an adjustment tool and often need to be
loosened in order to remove the drum. They also need to be tightened
after you replaced the shoes and re-install the drum. Retract them and
your diameter will be less than the drum.
>
> 4. Where the maximum diameter of 297mm was stamped on the drum itself:
> <http://www.bild.me/bild.php?file=9428041drum_brakes_3.jpg>
>
> 5. It was hard to get the drum back on even with the parking brake released
> from the cabin, so I had to use a mallet to bang it back on:
> <http://www.bild.me/bild.php?file=2434045drum_brakes_4.jpg>


Back to the adjuster.
>
> The main question is whether I'm supposed to *disconnect* the cable for the
> parking brake when working on the drums, and particularly when I put the
> new shoes on after I buy them.
>

The parking brake cable doesn't need to be removed, assuming it's
functioning properly. Just ensure the parking brake is not engage when
replacing shoes. The parking brake assembly will be removed when the
shoes are replaced.

> Also, only one shoe is worn, and it's the front shoe, and it's been on
> there for 175K miles, but I wonder if the shoes can be switched, so that
> the front shoe is in the rear and the rear shoe is in the front, since they
> wore so unevenly (sort of like rotating tires).
>

Much depends on the vehicle. Many shoes are identical and it doesn't
matter if they are placed in front or rear. Others are specific and
require proper position and seating. In your case, the shoes appear to
be the same but that wear is something I wouldn't simply "rotate" with
the other side. One side wearing more than the other is not normal and
should be checked, repaired/replaced then install new shoes with the
proper even thickness.

> But mainly I'm not sure what the procedure is for the parking brake cable.
> Can you advise?
>


  #4  
Old January 8th 18, 07:34 PM posted to alt.home.repair,rec.autos.tech
Mad Roger
external usenet poster
 
Posts: 57
Default Drum brakes - do you disconnect the parking brake cable?

On Mon, 8 Jan 2018 07:03:33 -0500,
Meanie wrote:

> It appears the one shoe is unevenly worn.


Thanks for your help as this is my first set of drum brakes ever.

This is a side view closeup of the front unevenly worn shoe:
https://s13.postimg.org/mezt8lvs7/brakes_drum_4.jpg

I had been, for years, looking through the peep hole, but that showed a lot
of meat on the shoes. You really have to remove the drum to see the actual
shoe, so, after 175K miles on the same shoes, I finally removed the drum
and noticed that the front show lower end, is worn tapering to the middle,
while the rest of the shoes are just fine.

> Could be a bad cylinder or
> another stuck part such as the adjuster. Check them and replace/repair
> if needed.


Thanks for that advice.

The cylinder seems to not be leaking but that's all I can tell.
There have been no unusual braking events so I'm not debugging anything.

I googled a bit, and it seems "normal" for Toyota 4Runner rear brake shoes
to wear most in the front show on the bottom half. Something to do with the
geometry. I can't complain, as the shoes definitely are original so 20
years is a long time for a brake shoe to finally wear out.

>> 3. I measured the drum to be 2mm smaller than the maximum diameter:
>> <http://www.bild.me/bild.php?file=9335528drum_brakes_2.jpg>

>
> Maximum diameter of what?


The drum:
http://www.bild.me/bild.php?file=942...m_brakes_3.jpg

In that photo you can see that the inside of the drum has a molded in
maximum diameter of 297mm. I assume that means the maximum diameter.

My calipers are in US measurements where 11.615 inches converts to about
295mm.

So I assume the drum is good by 2mm in thickness.

> Are you aware of the adjusters? Each side has
> one and it sits under the cylinder behind the hub.


Yes. This vehicle adjusts automatically when you brake in reverse, so I've
never dealt with them - but I am going to have to back them out for sure
when I put the new brake shoes on.

You can see the adjuster he
https://s13.postimg.org/senkcelrb/brakes_drum_1.jpg

I'm just not sure what we're supposed to do about the parking brake cable
linkages. I don't know yet if they have to be disconnected when putting in
new brake shoes.

You can see the parking brake cable he
https://s13.postimg.org/5egwznnt3/brakes_drum_2.jpg

> It's job is to keep the shoes against the drum and is automatically
> adjusted when the parking brake is used. Often, this is the reason why
> drums are difficult to remove. They are adjusted from the other side
> through an opening using an adjustment tool and often need to be
> loosened in order to remove the drum. They also need to be tightened
> after you replaced the shoes and re-install the drum. Retract them and
> your diameter will be less than the drum.


I understand what you're saying, which is that the brake shoes may be
"wedged" against the drum, but I had the vehicle in the air and the parking
brake off, so, any wedging shouldn't be too strong.

This is a closeup of the parking brake cable connection to the shoes:
https://s13.postimg.org/b2n7qr2hz/brakes_drum_3.jpg

As it was, putting the two 2-inch long 8mmx1.25 bolts in the two holes for
the purpose pushed the drum off easily. I had to squish the shoes a bit to
get the drum back on - and if necessary - I would have twisted the adjuster
- but I didn't need to.

> The parking brake cable doesn't need to be removed, assuming it's
> functioning properly. Just ensure the parking brake is not engage when
> replacing shoes. The parking brake assembly will be removed when the
> shoes are replaced.


Oh. OK. The parking brake seems to be a thick black cable that comes in at
the bottom of these shoes.

> Much depends on the vehicle. Many shoes are identical and it doesn't
> matter if they are placed in front or rear. Others are specific and
> require proper position and seating. In your case, the shoes appear to
> be the same but that wear is something I wouldn't simply "rotate" with
> the other side. One side wearing more than the other is not normal and
> should be checked, repaired/replaced then install new shoes with the
> proper even thickness.


I think I'll replace the shoes, but since they lasted 20 years, I was just
wondering if "rotating" them every two or three or five years would have
extended the life of them.

It's a late 90's 4Runner.
  #5  
Old January 8th 18, 11:20 PM posted to alt.home.repair,rec.autos.tech
Meanie[_3_]
external usenet poster
 
Posts: 2
Default Drum brakes - do you disconnect the parking brake cable?

On 1/8/2018 1:34 PM, Mad Roger wrote:

>
> Thanks for your help as this is my first set of drum brakes ever.
>
> This is a side view closeup of the front unevenly worn shoe:
> https://s13.postimg.org/mezt8lvs7/brakes_drum_4.jpg
>
> I had been, for years, looking through the peep hole, but that showed a lot
> of meat on the shoes. You really have to remove the drum to see the actual
> shoe, so, after 175K miles on the same shoes, I finally removed the drum
> and noticed that the front show lower end, is worn tapering to the middle,
> while the rest of the shoes are just fine.


>
> The cylinder seems to not be leaking but that's all I can tell.
> There have been no unusual braking events so I'm not debugging anything.


They don't always have to leak. I've had a few that were stuck due to
some rust within the cylinder. I just replaced them since they were
cheap back in the days of yore. Though, I did take one apart and freed
it up with some cleaning. It appeared to work fine after that.
>
> I googled a bit, and it seems "normal" for Toyota 4Runner rear brake shoes
> to wear most in the front show on the bottom half. Something to do with the
> geometry. I can't complain, as the shoes definitely are original so 20
> years is a long time for a brake shoe to finally wear out.


I can't speak for normality but I just find it odd that it would wear
like that when there isn't a bad part. Usually, I would see one show
worn more so than the other, but never a tapered wear.
>
>>> 3. I measured the drum to be 2mm smaller than the maximum diameter:
>>> <http://www.bild.me/bild.php?file=9335528drum_brakes_2.jpg>

>>
>> Maximum diameter of what?

>
> The drum:
> http://www.bild.me/bild.php?file=942...m_brakes_3.jpg
>
> In that photo you can see that the inside of the drum has a molded in
> maximum diameter of 297mm. I assume that means the maximum diameter.
>
> My calipers are in US measurements where 11.615 inches converts to about
> 295mm.
>
> So I assume the drum is good by 2mm in thickness.
>
>> Are you aware of the adjusters? Each side has
>> one and it sits under the cylinder behind the hub.

>
> Yes. This vehicle adjusts automatically when you brake in reverse, so I've
> never dealt with them - but I am going to have to back them out for sure
> when I put the new brake shoes on.


Most adjusters work with the emergency/parking brake. Though, many
people rarely, if ever, use the parking brake and those adjusters can
rust up and stop pushing the shoe against the drum.
>
> You can see the adjuster he
> https://s13.postimg.org/senkcelrb/brakes_drum_1.jpg
>
> I'm just not sure what we're supposed to do about the parking brake cable
> linkages. I don't know yet if they have to be disconnected when putting in
> new brake shoes.
>
> You can see the parking brake cable he
> https://s13.postimg.org/5egwznnt3/brakes_drum_2.jpg


I have worked on many drum brakes and I have never had to remove a
parking brake cable. The cable is attached to the metal assembly and
that will just hang on the cable when you remove it and replace the
shoes. Though, if it's easy to remove and reattach, then there's no harm
in doing so.
>
>> It's job is to keep the shoes against the drum and is automatically
>> adjusted when the parking brake is used. Often, this is the reason why
>> drums are difficult to remove. They are adjusted from the other side
>> through an opening using an adjustment tool and often need to be
>> loosened in order to remove the drum. They also need to be tightened
>> after you replaced the shoes and re-install the drum. Retract them and
>> your diameter will be less than the drum.

>
> I understand what you're saying, which is that the brake shoes may be
> "wedged" against the drum, but I had the vehicle in the air and the parking
> brake off, so, any wedging shouldn't be too strong.


Agreed. There should be a slight drag and minor friction when you turn
the drum, but never should be too tight where it's difficult to remove
the drum.
>
> This is a closeup of the parking brake cable connection to the shoes:
> https://s13.postimg.org/b2n7qr2hz/brakes_drum_3.jpg
>
> As it was, putting the two 2-inch long 8mmx1.25 bolts in the two holes for
> the purpose pushed the drum off easily. I had to squish the shoes a bit to
> get the drum back on - and if necessary - I would have twisted the adjuster
> - but I didn't need to.
>
>> The parking brake cable doesn't need to be removed, assuming it's
>> functioning properly. Just ensure the parking brake is not engage when
>> replacing shoes. The parking brake assembly will be removed when the
>> shoes are replaced.

>
> Oh. OK. The parking brake seems to be a thick black cable that comes in at
> the bottom of these shoes.


Yes, attached to the metal assembly which turns that adjuster.
>
>> Much depends on the vehicle. Many shoes are identical and it doesn't
>> matter if they are placed in front or rear. Others are specific and
>> require proper position and seating. In your case, the shoes appear to
>> be the same but that wear is something I wouldn't simply "rotate" with
>> the other side. One side wearing more than the other is not normal and
>> should be checked, repaired/replaced then install new shoes with the
>> proper even thickness.

>
> I think I'll replace the shoes, but since they lasted 20 years, I was just
> wondering if "rotating" them every two or three or five years would have
> extended the life of them.
>
> It's a late 90's 4Runner.
>


All I can say is I've never "rotated" brake shoes, since IMO, they were
cheap when I used to work on many cars. I can sympathize when only one
shoe is worn while the other(s) have ample thickness. I hate to see such
waste. The choice is yours since it appears the shoes are the same on
each side, you could simply swap them and ensure that drag and minor
friction partake when you reinstall the drum. Honestly, if it were me in
my youth as a poor teen working on my own car, that's what I would do.
But now that I'm a wealthy millionaire (that's tough to say without
laughing) Ok, now that I'm financially stable, I would just buy them and
install. Since you have to remove all the hardware anyway, installing
new shoes would be the best option.

  #6  
Old January 9th 18, 12:41 AM posted to alt.home.repair,rec.autos.tech
Mad Roger
external usenet poster
 
Posts: 57
Default Drum brakes - do you disconnect the parking brake cable?

On Mon, 8 Jan 2018 17:20:28 -0500,
Meanie wrote:

>> Yes. This vehicle adjusts automatically when you brake in reverse, so I've
>> never dealt with them - but I am going to have to back them out for sure
>> when I put the new brake shoes on.

>
> Most adjusters work with the emergency/parking brake. Though, many
> people rarely, if ever, use the parking brake and those adjusters can
> rust up and stop pushing the shoe against the drum.


I have since found out that you are correct and I was wrong.
Reversing won't work to adjust the drums.
The parking brake lever ratchets the adjustment.
My bad.
  #7  
Old January 8th 18, 07:45 PM posted to alt.home.repair,rec.autos.tech
Clare Snyder
external usenet poster
 
Posts: 56
Default Drum brakes - do you disconnect the parking brake cable?

On Mon, 8 Jan 2018 07:03:33 -0500, Meanie > wrote:

>
>> Also, only one shoe is worn, and it's the front shoe, and it's been on
>> there for 175K miles, but I wonder if the shoes can be switched, so that
>> the front shoe is in the rear and the rear shoe is in the front, since they
>> wore so unevenly (sort of like rotating tires).
>>

>Much depends on the vehicle. Many shoes are identical and it doesn't
>matter if they are placed in front or rear.

Define "many"

Only vehicles with "twin leading shoe" brakes use the same shoe front
and back - and I'm not aware of ANY vehicle built with twin leading
shoe brakes since the early seventies - and then only British
vehicles. The leading and trailing shoe are generally of different
lengths as well as often different friction materials.

> Others are specific and
>require proper position and seating. In your case, the shoes appear to
>be the same but that wear is something I wouldn't simply "rotate" with
>the other side. One side wearing more than the other is not normal and
>should be checked, repaired/replaced then install new shoes with the
>proper even thickness.


Actually it IS common - and considered normal, for the "leading shoe"
to wear differently than the "trailing shoe" on a servo type (self
energizing) brake system - which virtually all recent (modern) drum
brake systems are. the leading shoe contacts the drum, and the drag
(friction) on that shoe rotates the shoe through the linkage between
shoes, forcing the trailing shoe more firmly in contact with the drum.
This enhances the brake action beyond what would be possible strictly
by the hydraulic force from the wheel cyls.
>
>> But mainly I'm not sure what the procedure is for the parking brake cable.
>> Can you advise?
>>

It generally unhooks from the activbation lever connected to the
brake shoes. On soime cars the lever unhooks easily from the shoe and
does not NEED to be disconnected from the cable

Again - I would ADVISE you (the OP) to have a mechanic properly
repair the brakes.
  #8  
Old January 8th 18, 08:10 PM posted to alt.home.repair,rec.autos.tech
Mad Roger
external usenet poster
 
Posts: 57
Default Drum brakes - do you disconnect the parking brake cable?

On Mon, 08 Jan 2018 13:45:36 -0500,
Clare Snyder wrote:

> It generally unhooks from the activbation lever connected to the
> brake shoes. On soime cars the lever unhooks easily from the shoe and
> does not NEED to be disconnected from the cable
>
> Again - I would ADVISE you (the OP) to have a mechanic properly
> repair the brakes.


This net picture seems to show the rear drum brake setup reasonably well.
https://s13.postimg.org/hy7ga57c7/Rear_Brakes_1.jpg

I wonder why they put drum brakes in this vehicle when most are disc?
  #9  
Old January 8th 18, 09:37 PM posted to rec.autos.tech
dsi1[_11_]
external usenet poster
 
Posts: 269
Default Drum brakes - do you disconnect the parking brake cable?

On Monday, January 8, 2018 at 9:10:54 AM UTC-10, Mad Roger wrote:
>
> This net picture seems to show the rear drum brake setup reasonably well.
> https://s13.postimg.org/hy7ga57c7/Rear_Brakes_1.jpg
>
> I wonder why they put drum brakes in this vehicle when most are disc?


Drum brakes in the rear work perfectly fine for most vehicles because most of the braking is done with the front brakes. The reason 4 wheel disks are popular are mostly because people want it because it sounds cool. The problem with disk brakes is that it's less effective as parking brakes. Some rear disk brake systems will have an integrated brake drum and separate mechanical drum brake system to use as a parking brake.

You should know that the starwheel adjuster will have left and right parts that are not interchangeable. One side will have a right handed thread.

To set the initial clearance, start with the adjuster completely in, then turn it out a couple of turns. If the drum slips on easily, turn the wheel out more turns until you feel some resistance. Once you get the drum on, step on the brake to center the shoes. You might then have to adjust the clearance some more. Set the shoe clearance until you hear some light brushing when turning the drum.
  #10  
Old January 8th 18, 10:20 PM posted to alt.home.repair,rec.autos.tech
Tekkie®
external usenet poster
 
Posts: 72
Default Drum brakes - do you disconnect the parking brake cable?

Mad Roger posted for all of us...


>
> On Mon, 08 Jan 2018 13:45:36 -0500,
> Clare Snyder wrote:
>
> > It generally unhooks from the activbation lever connected to the
> > brake shoes. On soime cars the lever unhooks easily from the shoe and
> > does not NEED to be disconnected from the cable
> >
> > Again - I would ADVISE you (the OP) to have a mechanic properly
> > repair the brakes.

>
> This net picture seems to show the rear drum brake setup reasonably well.
> https://s13.postimg.org/hy7ga57c7/Rear_Brakes_1.jpg
>
> I wonder why they put drum brakes in this vehicle when most are disc?


Money, probably existing design...

--
Tekkie
 




Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
cj5 rear brake (drum) parking/emergency brake lever csdude Jeep 0 March 23rd 10 03:19 PM
cj5 rear brake (drum) parking/emergency brake lever csdude Jeep 7 March 23rd 10 09:01 AM
Parking brake/Rear drum sticking on Rabbit Bryan K. Walton VW water cooled 9 March 19th 06 01:44 PM
Parking Brake Cable and MM LCA Installation [email protected] Ford Mustang 1 November 4th 05 02:45 AM
Rear Parking Brake Cable Paul Garza Ford Mustang 3 May 14th 05 08:45 AM


All times are GMT +1. The time now is 09:06 PM.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2018, Jelsoft Enterprises Ltd.
Copyright ©2004-2018 AutoBanter.
The comments are property of their posters.