1971 Bus rear brake cylinders

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richard123vmt
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1971 Bus rear brake cylinders

Post by richard123vmt » Sun Jul 24, 2016 7:14 pm

It was built in 0/71. The parts list make a change in 07/71 from 22.2 to 23 mm wheel cylinders. So I would need the 22.2 mm. But could I substitute the 23mm? I think any better rear braking would be welcome. want to know if the two parts will bolt up identically. This has got to be a tidbit that many bus owners know. Thanks in advance.

Owen Snell
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Re: 1971 Bus rear brake cylinders

Post by Owen Snell » Mon Sep 12, 2016 1:37 pm

Buy both from someone who does returns.

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Marc
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Re: 1971 Bus rear brake cylinders

Post by Marc » Mon Sep 12, 2016 3:01 pm

The shoe frame shape was changed when the 23.8mm wheel cylinders were adopted, then again in Jan 1973. It's been 30 years since I last messed with this but IIRC the same backingplates and drums were used from `71-`79.

I'm pretty certain that you'd need to update the shoes to use the `72-`79 211-611-047F wheel cylinders, the late`73-`79 style would be the way to go for maximum parts availability in the future.
The e-brake lever attachment underwent changes twice so if you update the shoes you'll also need to be sure you have the compatible levers/hardware. Can't recall if the springs interchange so better grab them too if you go to the boneyard.

`71 only: http://images.thesamba.com/vw/classifie ... 187713.jpg
`72-early`73: http://images.thesamba.com/vw/classifie ... 766516.jpg
late `73-`79: http://kieftenklok.nl/shop/images/stori ... 537N_1.jpg

kreemoweet
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Re: 1971 Bus rear brake cylinders

Post by kreemoweet » Mon Apr 24, 2017 1:07 pm

72-79 rear wheel cylinders are not installable in an otherwise stock 71 brake setup because the mounting provision changed from the 71 method.
Even if they could be, it would not be a good idea. The wheel cylinders need to match all the other brake system parts, including the master
cylinder. Bigger is not always better.

It was a plausible theory that converting to the 73-79 brake components would enhance future parts availability, but it has turned out not to be the case.
I made that conversion a few years ago, and then quickly discovered that the 73-79 brake shoes are no longer being made anywhere in the world, and
the shoes all the vendors are selling as 73-79 shoes are actually Vanagon shoes (minus the ancillary self-adjusting hardware). There is no way in hell that the Vanagon shoes will perform in the same manner as the bus shoes were designed to do, and vendors who claim otherwise should not be believed.
https://www.thesamba.com/vw/forum/viewt ... highlight=

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Marc
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Re: 1971 Bus rear brake cylinders

Post by Marc » Mon Apr 24, 2017 8:09 pm

kreemoweet wrote:
Mon Apr 24, 2017 1:07 pm
I...discovered that the 73-79 brake shoes are no longer being made anywhere in the world...
I was unaware of that issue - back in the `80s, of course, it was not a problem (you could buy them direct from the dealer then if you wanted to).
Having OEM shoe frames relined locally seems like the best option, especially if your drums have been turned a few times - read on:

A little-known fact is that ALL ACVW brake drums may be turned .040" beyond the "maximum" dimension cast into the drum (the only problem is finding a shop willing to do so). That measurement is based upon being able to achieve a satisfactory radius match when using off-the-shelf "standard" shoes. VW allows going a millimeter bigger IF you use "oversized" linings that are .020" thicker than the standards. Even 35 years ago we were taking advantage of this loophole to give customers the option of saving some money by not buying new drums when theirs were a little past the first limit. Oversize shoes could be ordered through the dealer but they seldom had them in stock so it was more expedient to have them built locally. We had our own radius-grinding machine back then; due to EPA (and some states') regulations those are rarely found anymore, but any specialist shop that relines shoes will have one and can arc oversize linings for proper fit.

See the first remark on p125 of the `72 "Without Guesswork" VW workshop booklet: http://oacdp.org/wog72/124_b.png
Last edited by Marc on Mon Apr 24, 2017 8:32 pm, edited 1 time in total.

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Re: 1971 Bus rear brake cylinders

Post by Marc » Mon Apr 24, 2017 8:27 pm

Here's how the shoes changed over the years from 1971 to 1991:

1971: 211 608 537J                 (10200) http://www.autohausaz.com/images/10200.jpg

1972 (+`73 thru VIN 2x3 2102 496) 211 609 537K (10215) http://www.autohausaz.com/images/10215.jpg

Late`73-`79 211 609 537N (10231) http://www2.cip1.com/v/vspfiles/photos/ ... 37-N-2.jpg LEVERS MAY NOT BE INCLUDED

Vanagon `80-`91 251 609 537      (10279) http://www.autohausaz.com/images/10279.jpg - note the different location of the top return spring hole and the smaller bottom hole compared to the 10231 that kreemoweet mentioned. "Legit" 10231s are still out there, but getting hard to find.

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