Folding over brake shoes

jacobe · Posted: Fri Oct 17, 2014 8:44 am Post subject: Folding over brake shoes

The brake shoes on the rear brakes on my sandrail have been folded up multiple times while using the cutting brakes. What is happening is that the brake shoe flange is less than half the width of the cut-away in the wheel cylinder where the flange on the shoe rides. Then on a random use of the cutting brake the flange on the brake shoe will bend and fold up the shoe and the cylinder blows out. The brakes are adjusted appropriately and the drum is in the allowable wear limits.

After the first occasion the I just replaced the brakes shoes and moved on. Then it happened again so cut down the lever for the cutting brake so I couldn't be as rough with them, but last weekend it occurred again. I am intending on welding another flange to the existing flange on the shoes so that it will be twice as thick and completely fill the slot in the cylinder.

Has anyone else had any experience with this. I tried searching the forums but didn't find anything real helpful.

jsturtlebuggy · Posted: Fri Oct 17, 2014 9:57 am Post subject:

Yes it happen to me back in the 1970s on my sand buggy at the time.
All I did at the time was keep replacing shoes until I learned how hard I could pull/push on steering brake handle.
At the time I was using a Neal 5/8" single handle with 25mm rear wheel cylinders (No longer available).
The biggest wheel cylinders now are the Super Beetle front wheel cylinders 23mm.
What your combination of steering brake size, wheel cylinder size, brake shoe size?
_________________
Joseph
Fair Oaks/Orangevale, CA
Elrod Motorsports
Motion Tire Motorsports
Having fun with Dune Buggies since 1970
Into Volkswagens since 1960

jacobe · Posted: Fri Oct 17, 2014 10:14 am Post subject:

The cylinders are 23mm, ran larger size on the rear because of the weight distribution of a sandrail. I believe the bore for the cutting brakes is 3/4" but I am not positive on that. I don't recall the size of the drum but it is the larger size of what was offered on a 70 something super I think.

Figured if welding up the brake flange didn't work I would use a smaller cylinder next.

jsturtlebuggy · Posted: Fri Oct 17, 2014 10:42 am Post subject:

Sounds like you are using Bug 9in drums.
Type III use a 9 3/4" drums.
Yes using a smaller size wheel cylinders will change the leverage between them and the steering brake.
Using a steering brake is a learning experience. Originally designed using 5/8" size in steering brake against either 17mm (11/16in) or 19mm (3/4in) stock rear wheel cylinders. So not as much leverage between the two.

You may want to switch to disc brakes to eliminate the problem. Many cheaper options available now.
A cheap way to make your own disc brakes is to use type III rear brake hubs (drums are removable) and machine them down to fit Porsche 914 rear rotors to fit. And then make brackets to fit type III calipers. CB Performance makes a kit that basically the same thing. If you need to go from 4lug to wide 5 for wheels, adapters are available.
_________________
Joseph
Fair Oaks/Orangevale, CA
Elrod Motorsports
Motion Tire Motorsports
Having fun with Dune Buggies since 1970
Into Volkswagens since 1960

Vanapplebomb · Posted: Sat Oct 18, 2014 1:04 pm Post subject:

Sorry about hijacking this thread but I have the 23.8mm front super cylinders in the back. I'm tossing around the idea of a cutting brake as well. Would 3/4in cylinders be better than 5/8in for the larger wheel cylinders?
_________________
1800 Type 4 Berrien 295

http://www.thesamba.com/vw/forum/viewtopic.php?t=487021

jsturtlebuggy · Posted: Sat Oct 18, 2014 4:11 pm Post subject:

If you are talking about 3/4" size steering brake, I would say yes if you don't have much experience in using a steering brake.
With using that large of wheel cylinder (I am using them with the type III wide 5 rear brakes with a 3/4in steering brake), steering brake handle/handles will not travel as far and will be firmer then a 5/8" one.
Plus if you ever go with disc brakes, you all ready have a steering brake that works with them.
_________________
Joseph
Fair Oaks/Orangevale, CA
Elrod Motorsports
Motion Tire Motorsports
Having fun with Dune Buggies since 1970
Into Volkswagens since 1960

Vanapplebomb · Posted: Sun Oct 19, 2014 1:07 pm Post subject:

Thanks for the input!
_________________
1800 Type 4 Berrien 295

http://www.thesamba.com/vw/forum/viewtopic.php?t=487021


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