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Forum Index : Other Stuff : Drum brake issue

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OA47

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Joined: 11/04/2012
Location: Australia
Posts: 640
Posted: 09:25am 09 Sep 2019
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Thought I would throw this one up. My daughter in her wisdom has purchased a mid seventies vehicle and being dad I thought I would at least make it as safe as possible. I checked the front drum brakes and saw that they were nearly worn out so along with some other parts I took a sample of the shoes to the brake shop an purchased some replacement shoes. All went together Ok but although the drums rotate on their own they lock up when I tighten the wheel studs. Any help with this issue would be greatly appreciated.

(I am not the most favorite dad at the moment)
OA47
 
renewableMark

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Joined: 09/12/2017
Location: Australia
Posts: 1315
Posted: 09:43am 09 Sep 2019
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Sounds like they are not the correct shoes or you have fitted them in the wrong way.

If you tighten the wheel on and they lock up then it sounds like they are getting jammed against the drum itself, thus locking it all up.

Is this what you mean when you say "tighten the wheel studs"?
Cheers Caveman Mark
Off grid eastern Melb
 
OA47

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Joined: 11/04/2012
Location: Australia
Posts: 640
Posted: 09:58am 09 Sep 2019
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Thanks Mark, I think the shoes are the right ones as I took a sample to the shop and they measured them and checked them against the old ones. Sorry I did mean tightening the wheel nuts.

OA47
 
renewableMark

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Joined: 09/12/2017
Location: Australia
Posts: 1315
Posted: 10:59am 09 Sep 2019
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This is what I am familiar with (pic ripped off net)

What are you tightening to cause a lockup?
Cheers Caveman Mark
Off grid eastern Melb
 
SimpleSafeName

Regular Member

Joined: 28/07/2019
Location: United States
Posts: 66
Posted: 11:36am 09 Sep 2019
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A picture of your brake would be helpful.

I always did mine one side at a time because of the multitude of different ways that they could be installed.
 
Warpspeed
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Joined: 09/08/2007
Location: Australia
Posts: 2739
Posted: 09:42pm 09 Sep 2019
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Rear drum brakes can be tricky, because the hand brake complicates things a lot.

But front brakes are much simpler. It sounds to me as if the wheel cylinder pistons are extended, which they will do as the brake shoes wear much thinner.

Try forcing each piston back into the wheel cylinder bore, by applying some leverage from a screwdriver. The pistons should move smoothly, but take considerable effort to move. There is a very faint chance that one or both pistons may be rusted or jammed solid, but its unlikely.

Be aware though, that pushing the pistons back will force a lot of brake fluid to go back up into the master cylinder, and it may overflow. So put something underneath to catch any overflow. First remove the cap on top of the brake fluid reservoir, otherwise the returning fluid will have nowhere to go and that may stop the wheel pistons from moving back far enough.

With both the pistons pushed back, that will move both brake shoes inwards.
New brake shoes will be a lot fatter than the worn ones, and will simply jam if you try to replace the drum without first pushing the pistons back.

Replace the drum and wheel and it should all rotate freely.
The brake pedal will now hit the floor when you first apply the brakes. That is to be expected.

Pump the brake pedal a few times, not too quickly, but make sure the fluid level in the brake reservoir does not drop too low. So after each couple of pumps, top up the fluid if necessary.  The brake pedal should come back up to its normal working height, and job done
Cheers, Tony.
 
renewableMark

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Joined: 09/12/2017
Location: Australia
Posts: 1315
Posted: 09:47pm 09 Sep 2019
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Whatever you have done, it wasn't correct, so even if it does get put together ok it's probably wise to get them checked by a mechanic.

Chris fix knows his stuff and does good videos.
here

Scotty is a bit of a prawn but also knows his stuff.
here

BTW where are you? Someone might be close by that could help.
Edited 2019-09-10 07:49 by renewableMark
Cheers Caveman Mark
Off grid eastern Melb
 
OA47

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Joined: 11/04/2012
Location: Australia
Posts: 640
Posted: 10:27pm 09 Sep 2019
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Thanks Mark, I think the shoes are the right ones as I took a sample to the shop and they measured them and checked them against the old ones. Sorry I did mean tightening the wheel nuts.

OA47
 
Warpspeed
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Joined: 09/08/2007
Location: Australia
Posts: 2739
Posted: 10:55pm 09 Sep 2019
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The new shoes are going to be larger than the old ones, simply because the linings are unworn and much thicker.

The drums are going to jam unless you make allowance for that.

Can you take a photograph of your brakes with the drum off ? Or perhaps if you can tell us the exact make, year, and model a picture may be available on the internet.
Cheers, Tony.
 
renewableMark

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Joined: 09/12/2017
Location: Australia
Posts: 1315
Posted: 12:01am 10 Sep 2019
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You could go to a local wreckers, find the same car, pull it apart and take a bunch of photo's.
Or just get a mobile mechanic to come fix it.
Cheers Caveman Mark
Off grid eastern Melb
 
SimpleSafeName

Regular Member

Joined: 28/07/2019
Location: United States
Posts: 66
Posted: 01:48am 10 Sep 2019
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It could be as simple as running the E-Brake adjusted back together.
 
Warpspeed
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Joined: 09/08/2007
Location: Australia
Posts: 2739
Posted: 02:15am 10 Sep 2019
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Its a front drum brake.
Usually no automatic threaded wear adjuster (for the hand brake) to wind back.
Cheers, Tony.
 
OA47

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Joined: 11/04/2012
Location: Australia
Posts: 640
Posted: 02:17am 10 Sep 2019
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These front brakes are so simple with two shoes two springs and the pin retention. I spoke to the brake shop and there advice was that the new shoes had too much lining and even though the adjusters were fully back there was not enough clearance. This has been rectified by grinding about 1mm off the shoe at the point where the shoes fit into the slave cylinder slots.

Thank you for your contributions.
OA47
 
Grogster

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Joined: 31/12/2012
Location: New Zealand
Posts: 6878
Posted: 03:10am 10 Sep 2019
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Drum brakes can be fun sometimes!

When I redid the brakes on my '62 Velox, I referred to the technical specs, and as I could not get generic replacements, I had to have the original shoes re-padded and I could then specify the maximum thickness of the friction material, and so never had that problem.  But yeah, new shoes are generally a very close fit in the drums(having not worn at all yet), and so rear brake shoe adjusters have to be wound fully off and the handbrake re-adjusted to get the wheel to spin freely and handbrake to work correctly.

Front drum brakes don't generally have adjusters like the rear, they have two slave-cylinders rather then one like on the rear.

As with any car that you replace brake pads or shoes on, go easy on the brakes for the first week or so, to let the new pads/shoes bed-in.  Once they do that, I find all-round drum brakes are extremely good at stopping you - more friction surface area then pads and discs on the front.

BTW, you said 70's car: what make and model - just for my own interest...
Smoke makes things work. When the smoke gets out, it stops!
 
Davo99
Senior Member

Joined: 03/06/2019
Location: Australia
Posts: 160
Posted: 11:52am 10 Sep 2019
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If the car came out with disks, or a later model did that can be fitted, I'd be finding some and putting those on ASAP.

Drums when they get properly wet can be useless.  Make sure your Daughter knows this and show her how to test and dry them out if they do get wet. If she has only driven cars with Disks before, she could get a nasty shock if shes not aware.

I personally despise Drums with a passion for exactly the reasons mentioned. They are complicated, Finicky things that are a pain to work on and the grand scheme of things, Don't last that long ( wheel Cylinders) before they need replacing and frequent adjustment. They have no where near the stopping power in the wet despite what a lot of people say.

I remember when I was a kid, My father was the Spares manager at a dealership. He also used to move a fair few cars just talking to people which wasn't the done thing and rattled the salesmen a bit but He got on well with the boss and Pretty much did what he wanted as he used to make the place a lot of money with his  different ideas that always seemed to work.

I happened to go to work with him one day when his new company car was ready, a 5 Liter HQ premier with all the options boxes ticked.  Someone brought it round from the workshop for him and parked it at the door.
We got in it, Dad had a look around and then put the T bar in Drive and went to the edge of the driveway.... Where he locked the thing up in a massive skid.

One of the mechanics rushed over and asked what was wrong. Dad said I just put my foot on the brake and  the thing locked up. Mechanic laughed and said it's got disks on it, they are a lot different to drums. Dad said I'll say!

We went round he block and into the big carpark behind where Dad did a few practice  stops before Proceeding home.

Nice car that. Brother and I were fascinated with the power windows.
He had different ones a while then they gave him an SLR 5000. Dad was a bit annoyed about that and didn't want it. Had a go at the boss and said why can't I have another premier?

The reason he didn't want it was the same reason he didn't want the GTR Xu-1 he had before.  He got tired of having to get a cab home every time he went out anywhere in it and it got knocked off.  Had the SLR about a month and it too went despite the cut off switch in the boot and the " Yellow Light " alarm.  Which seems to work only when  it was locked in the shed and or the workshop but didn't actually stop the thing getting flogged.

3rd time it went Dad was pretty ticked off and told the boss to give him a premiere or a statesman or I'll got find some place that will.  
Some times he'd bring home SLR's cause they didn't have anywhere to put them and didn't want to leave them in the yard. He would also get a Statesman Caprice now and then if they sold his car as a demo but He liked his premiers better.

He also would get Monaros but didn't like them that much either with us kids having to climb in and out. Did manage to bring one home and sell it to the neighbour.

What those cars would be worth now.
 
SimpleSafeName

Regular Member

Joined: 28/07/2019
Location: United States
Posts: 66
Posted: 12:07pm 10 Sep 2019
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  Warpspeed said  Its a front drum brake.
Usually no automatic threaded wear adjuster (for the hand brake) to wind back.


Ah, I missed that. No there wouldn't be. :)
 
Davo99
Senior Member

Joined: 03/06/2019
Location: Australia
Posts: 160
Posted: 12:16pm 10 Sep 2019
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Some cars actually had the handbrake ( only disks I know of myself) on the front.
Subaru was one of them but I think some of the Euros had it too. Skoda and  Citroen come to mind.
 
isaiah

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Joined: 25/12/2009
Location: United States
Posts: 303
Posted: 04:07pm 11 Sep 2019
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There are kits you  can put disks on all 4 wheels and have some breaks.
URL=http://www.motherearthnews.com/Renewable-Energy/1973-11- 01/The-Plowboy-Interview.aspx>The Plowboy Interview[/URL>
 
Warpspeed
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Joined: 09/08/2007
Location: Australia
Posts: 2739
Posted: 01:15am 12 Sep 2019
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Probably better to put the money into the piggy bank towards a better "next" vehicle.

I think we can all remember our first car, pretty crappy though it may have been in retrospect.  It was at the time, a most wonderful car to us, even with drum brakes
Cheers, Tony.
 


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