[T3] 69 Master Cylinder?

Jim Adney jadney at vwtype3.org
Mon Sep 27 08:36:19 PDT 2021

On 26 Sep 2021 at 20:32, Jeff Palmer wrote:

> We have replaced the brake lines but found the master cylinder leaking,
> and internally itTMs pitted pretty badly. 

I regularly rebuild our MCs, but there is a problem with the original '68-9 MC 
design. The original part had a double bore, shown in the Bentley manual, 
that added a shuttle piston to actuate the brake warning light. This bore rusts 
and is impossible to clean, because it's so small. Also, replacement seals 
are NLA.

The best solution is to replace with a late style MC, as introduced in late '71. 
Those can still be found online or on ebay. While expensive, it's a much 
better solution than trying to stick with the '68-9 version.

To install the late version, you will also need to replace your early 2-pin 
brake light switches with the later 3-pin switches, the brake light wiring 
harness with a harness from a '70-3 harness, and the hard line to the RF 

I have the late MC, the late switches, and the late hard line, but I've sold all 
the late wiring harnesses that I once had. If you can find a late parts car 
anywhere, that harness should be there. Unfortunately, shipping prices 
between Canada and the US are rediculous, so you should probably try to 
find replacements in Canada.

Good luck getting your '69 AT Notch back on the road. Is it still FI? I don't 
know if they were, in Canada, or wherever this car originally came from.

Jim Adney, jadney at vwtype3.org
Madison, Wisconsin, USA

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