Corvair DiagramCorvair Photo
Corvair Center
home forum corvairs calendar links Corvair Podcast
California Corvairs
Clarks Corvair
Clarks Corvair
“CORSA"



Chevy Corvair License Plate
Chevy Corvair Chrome Wheel
Corvair Center Forum :  Corvair Center Phorum The fastest message board... ever.
Corvair Center 
Pages: 12Next
Current Page: 1 of 2
How to make Early Brakes Work
Posted by: vairmech ()
Date: January 12, 2018 05:57PM

I get the 189 brake shoes from either Advance auto or O'Reiley's. I have said this before that they look and sort of feel like a carbon metallic material. There are a couple of things I need to let some of you know, I grew up working on drum brakes. I know what they should look like and the way the originals were made.
So with that here is what you get from the store now, if you notice all the linings are the same length. Brake shoes need a primary and a secondary shoe. It used to be back in the day that the primary shoe was a softer material and it was also a smaller area shoe than the secondary.




So what do you do? You modify the shoes to be like the original shoes used to be, it isn't hard. All you need to do is make 2 of the shoes shorter than the other two. All you need is a hack saw a stiff putty knife that has a bit of an edge and a hammer.






I took of about an inch and also a half inch on the other side as is apparent in the above pictures. I didn't measure anything but I did use the first piece I cut I used as a guide. If you look close where the small cut was done I did use the dimple as a guide for the first cut.



But wait, for $19.99, Oh, not a commercial!
I also chamfer the ends while this is not a requirement it does help quiet any shoe noise or possible issues with leading square ends. I just used my bench grinder.



Here is what you end up with, primary and secondary shoes!




Then just for grins here is the shoes installed on the car. Remember, the small shoe ALWAYS goes in the front. And the self adjuster star ALWAYS goes to the rear.





After the shoes are installed you are not done! You need to go out and drive the car in a specific manner. After you make sure the car will at least stop you need to accelerate to about 60 mph once there you need to stand on the brakes, not lock up the brakes but you want to stop hard and fast. Once you are slowed to about 10 mph accelerate again to 60 mph and do the same stop again. You may even feel the brakes are better than the first time. Accelerate for a third time to 60 and stop hard one more time. Now drive about a half mile without using any brake so they can cool. Turn around and start back using the brakes gently to slow for the turn. Head back and about half way back try the brakes, I bet they will feel really good with a light pedal pressure. Finish heading back and let the brakes cool. The next time you drive your car don't hit your head on the windshield.

Ken Hand
Handy Car Care
248 613 8586

Vairmech@aol.com

Options: ReplyQuote
Re: How to make Early Brakes Work
Posted by: American Mel ()
Date: January 12, 2018 06:17PM

Yes, I remember brake-shoes always coming as you have stated.

But, why?

And what difference does it make?

And why do brake manufacturers not consider it important today?

Truly curious, not trying to be Smart-Aleck.

.
-----------------------------------------------
WA. state, 1 mile south of the Canadian border,
I am not at the end of the world, but you can see it from here.
'66 Monza Coupe - 4spd, 140 Daily driver beater
'67 Monza Vert. - PG, 140 Daily driver beater

Options: ReplyQuote
Re: How to make Early Brakes Work
Posted by: 66vairman ()
Date: January 12, 2018 06:41PM

American Mel Wrote:
-------------------------------------------------------
> Yes, I remember brake-shoes always coming as you
> have stated.
>
> But, why?
>
> And what difference does it make?
>
> And why do brake manufacturers not consider it
> important today?
>
> Truly curious, not trying to be Smart-Aleck.


Like most cars from that era, except some 50's Chrysler products, the Corvair drum brakes are "Self Energizing". For a progressive pedal feel the front shoe has the shorter lining. When you apply the brakes the front shoe is pushed by the drum rotation (going forward) against the rear shoe with the longer linings. Incorrect linings lengths can result in higher pedal pressure or brakes that tend to lock up too easily.

Plenty on-line about this.

Nice job Ken.



Edited 1 time(s). Last edit at 01/12/2018 06:43PM by 66vairman.

Options: ReplyQuote
Re: How to make Early Brakes Work
Posted by: vairmech ()
Date: January 12, 2018 06:44PM

American Mel Wrote:
-------------------------------------------------------
> Yes, I remember brake-shoes always coming as you
> have stated.
>
> But, why?
>>>>>>>>>>>>>>>>>>>>
I'm not sure I can explain the why properly but the term self energizing comes to mind. I think the only way to get the self energizing is to have a smaller square inch area pushing on the larger shoe. When you have 2 shoes of the same size I think the self energizing part sort of goes away and makes for a higher pedal pressure.
> >>>>>>>>


> And what difference does it make?
> >>>>>>>>>>>>>>>>>>>>>>>>>
Obvious, better stopping power!
>>>>>>>>>>>


> And why do brake manufacturers not consider it
> important today?
>>>>>>>>>>>>>>>>>>>>>>>>>>>
Because the brake manufacturers of today don't know drum brakes because they are only interested in disc brakes. Also it is easier to just use 2 of the same size so you can standardize production.
>>>>>>>>>


> Truly curious, not trying to be Smart-Aleck.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
Not taken that way at all!

Ken Hand
Handy Car Care
248 613 8586

Vairmech@aol.com

Options: ReplyQuote
Re: How to make Early Brakes Work
Posted by: American Mel ()
Date: January 12, 2018 06:48PM

Thank-you gentlemen! thumbs upthumbs up

.
-----------------------------------------------
WA. state, 1 mile south of the Canadian border,
I am not at the end of the world, but you can see it from here.
'66 Monza Coupe - 4spd, 140 Daily driver beater
'67 Monza Vert. - PG, 140 Daily driver beater

Options: ReplyQuote
Re: How to make Early Brakes Work
Posted by: MattNall ()
Date: January 12, 2018 06:49PM

Ken what about "Arcing" the shoes to fit the drums, if needed?





MODERATOR
Sea Mountain, between Charleston Harbor and Coos Bay! SW Oregon Coast
Click HERE for My Website...Click HERE for My TechPages!
..............................110-PG.................................................Webered-Turbo

Options: ReplyQuote
Re: How to make Early Brakes Work
Posted by: vairmech ()
Date: January 12, 2018 07:18PM

That hasn't been needed to be done in about 40 years. With the molds they have the shoes are pretty constant in their radius. Unless you have NOS drums you could never arc the shoes properly for a larger drum.

I just took off a relatively new set of shoes because of contamination and the contact was probably at 75% and that is mostly because the drums were belled some. I put new shoes on this very car you see the shoes on and it stops Vairy well, almost as good as my late models.

Ken Hand
Handy Car Care
248 613 8586

Vairmech@aol.com

Options: ReplyQuote
Re: How to make Early Brakes Work
Posted by: Frank DuVal ()
Date: January 12, 2018 07:57PM

Mr. Bendix came up with this idea years ago. He said the Duo-Servo brakes harnessed the power of the rotating drum to help push the shoe against the drum.

Interesting is another source that says the dissimilar length shoes is because the front shoe (primary/short ling) helps push the rear shoe (secondary/long lining) into the drum, so the rear shoe wears faster. Therefore they made the front shoe short to even out the wear patterns!winking smiley

I like Ken's idea to make the shoes look like before, and that break in procedure used to be included with shoes!

Frank DuVal

Fredericksburg, VA

Options: ReplyQuote
Re: How to make Early Brakes Work
Posted by: flamingchariots ()
Date: January 12, 2018 08:57PM

This is very interesting topic.

With this break-in pattern, is there any chance of glazing the shoes?

Should/can riveted shoes be modified too?

Kevin
Medina, OH

Options: ReplyQuote
Re: How to make Early Brakes Work
Posted by: jmaechtlen ()
Date: January 12, 2018 09:11PM

My sneaky suspicion is that the front shoe doesn't do as much work, so it wouldn't wear as fast, so you could put less lining on it and save a bit of cost.
But if you don't make that many, it may be cheaper to make them all the same.

Options: ReplyQuote
Re: How to make Early Brakes Work
Posted by: American Mel ()
Date: January 12, 2018 10:25PM

flamingchariots Wrote:
-------------------------------------------------------
> This is very interesting topic.
>
> With this break-in pattern, is there any chance of
> glazing the shoes?
>
> Should/can riveted shoes be modified too?


Actually,
this method of "break-in" is EXACTLY what I always heard as a youngster, waaaaay back in the dark ages.
It seems that it was a pretty common practice back in the day.

.
-----------------------------------------------
WA. state, 1 mile south of the Canadian border,
I am not at the end of the world, but you can see it from here.
'66 Monza Coupe - 4spd, 140 Daily driver beater
'67 Monza Vert. - PG, 140 Daily driver beater

Options: ReplyQuote
Re: How to make Early Brakes Work
Posted by: vairmech ()
Date: January 13, 2018 04:45AM

flamingchariots Wrote:
-------------------------------------------------------
> This is very interesting topic.
>
> With this break-in pattern, is there any chance of
> glazing the shoes?
>
> Should/can riveted shoes be modified too?
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

Yes you can shorten the shoes, you just need to stay away from the rivets by at least a 1/4".

If you use riveted shoes personally I don't like the material if it is the grey to off white material. It feels waxy and I have never been able to get those shoes to work as well no matter the type of break in I used. As far as glazing? It is easier to do with the riveted shoes but more than likely you will get fading, (out gassing), before you glaze the shoes.

Ken Hand
Handy Car Care
248 613 8586

Vairmech@aol.com

Options: ReplyQuote
Re: How to make Early Brakes Work
Posted by: Wagon Master ()
Date: January 13, 2018 04:57AM

vairmech Wrote:
-------------------------------------------------------
> Personally I don't like
> the material if it is the grey to off white
> material.


Unless it's lighting or camera angle you're first 2 picture look like different shoe material. The linings you showed me at your shop look like the second one. Are these the ones you like?

Options: ReplyQuote
Re: How to make Early Brakes Work
Posted by: croderique ()
Date: January 13, 2018 06:36AM

Is this the same procedure for the LM or are the brakes that much different? I thought only difference is the brake drum / shoes were larger on the LM. Thanks, Chuck

Buckeye, AZ.
1966 Monza convertible 110 hp 4 speed Aztec Bronze with Bronze interior

Options: ReplyQuote
Re: How to make Early Brakes Work
Posted by: v8vair ()
Date: January 13, 2018 06:50AM

Ive always used the lead and trailing shoe, but when i hand my Porterfield racing shoes made they recommended a full lining on both shoes? More Contact. On my Carbo Tech Racing shoe they offered me the same choice but i went with the lead and trailing. Cant say ive tried the full shoes so just passing on what was offered.
Mike

Options: ReplyQuote
Re: How to make Early Brakes Work
Posted by: toms73novass ()
Date: January 13, 2018 07:46AM

Ken, Awesome write up! thumbs up smileys with beer

-Tom


63' Monza Spyder Convertable (in process) MY Build Thread
65' Monza MY Build Thread
73' NovaSS 454 Big block
86' BMW 325es
98' Dodge 2500 12v Cummins Diesel with 1200 lb torque!
98' VW Jetta TDI, for daughter
01' Audi Allroad Stage 3 twin turbo

NFCC
Grand Island, NY

Options: ReplyQuote
Re: How to make Early Brakes Work
Posted by: American Mel ()
Date: January 13, 2018 08:23AM

Am I the only one who thinks this may be a good candidate for going in the "Stickies" ? ? ?

.
-----------------------------------------------
WA. state, 1 mile south of the Canadian border,
I am not at the end of the world, but you can see it from here.
'66 Monza Coupe - 4spd, 140 Daily driver beater
'67 Monza Vert. - PG, 140 Daily driver beater

Options: ReplyQuote
Re: How to make Early Brakes Work
Posted by: Nickshu ()
Date: January 13, 2018 08:36AM

I recently bought a set of these as recommended by Ken. I am currently using the Clarks shoes and getting horrible brake fade (downright scary!) going downhill.

I called Ken asking about a disc brake conversion...he said just get these.

I have not had time to install them yet but once I do I will report back. Looking at them in the box they appear to be a much more aggressive compound than the smooth organic Clarks shoes.

**I will add that if you get the Wearever S189 pads from Advance Auto Parts they do not have to be modified - The are the same pads as shown above BUT they come with a short and a long side. There is no need to cut them.**

Nick
_______________________________________________________________________
1964 Monza Spyder Convertible #435 - Rotisserie restored - Check out my restoration thread here: [corvaircenter.com]
Recreational Mechanic/CORSA Member/COG Supporting Member/US Navy Veteran
Other fun car: Porsche 911 GT3
Boring daily drivers
Northern Colorado, USA



Edited 2 time(s). Last edit at 01/13/2018 08:39AM by Nickshu.

Options: ReplyQuote
Re: How to make Early Brakes Work
Posted by: RexJohnson ()
Date: January 13, 2018 10:08AM

I was told that the short front shoe was softer so that it would grab the drum and force the longer harder shoe tighter to the drum. That is why there is no anchor pin at the bottom so that the shoes can all rotate together wedging the longer shoe between the drum and the anchor pin.

RJ tools
Salem,Oregon

Options: ReplyQuote
Re: How to make Early Brakes Work
Posted by: Brizo ()
Date: January 13, 2018 02:27PM

The most common cause I've been seeing for weak brakes (especially on on EM's for some reason) is roughly machined shoe linings, and drums with a rough surface because they were re-surfaced too fast -(often a FLAP store ). Both of these factors combined can result in a very low percentage of shoe to drum contact. Plus, I've had several cases of small shoe contact area due to waaaay oversize drums!

Dan Brizendine,
'64 8door Greenbrier 140 PG. "In beautiful Wanamaker Indiana...with one stop light and 5 pizza shops"

Options: ReplyQuote
Pages: 12Next
Current Page: 1 of 2


Sorry, only registered users may post in this forum.
This forum powered by Phorum.