# brake upgrade questions for my 81 convertible



## 76sciroccoRelived (Jul 27, 2005)

I have a 1981 and have fitted the scirocco 16v rear brakes as well as vented front brakes like you =would see in a 1993 vw cabriolet. 

Mounted at the rear on the drivers side is the brake unit. I believe it is a proportoning unit? It has a large spring on it and all the lines from the master cylinder go to it then branch off.

I have a set of proportoning valves that go in the master cylinder. Do I need or better said, can I leave this rear unit in place? Is there a certain code # on the proportioning valves that I need at the master? I have a 22mm master ready to put in. Question is - Do I need the larger brake booster or can I go with the one I have.?

Thanks so much. !


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## Kazan (Feb 4, 2005)

What then do I do about the proportioning valve for the rear disk
> brakes?

If you use 9.4" front rotors, you need #533612151
If you use 10.1" front rotors, you need #533612151A 

Taken from Upgrading to 16V Scirocco Brakes 
http://www.scirocco.org/list/archives/2002/February/msg03521.html


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## Kazan (Feb 4, 2005)

" Here's why you can't run the later booster with the early master cylinder.

The MK I booster's internal rod protrudes slightly from the booster, by a few mm.



Whereas with the Late boosters the rod is about 25mm down inside the booster. "


As shown with pictures at the bottom of the page .

http://www.vwwatercooled.org.au/f20/how-mod-late-booster-mk1-11689.html

Some of the other stuff is about Right Hand Drive .

You MIGHT be able to use a late master cylinder with a early booster by making a 25mm spacer . 

If you changed the front brakes to the 10.1" /256mm with your rear disc and used the late booster and late master cylinder you would have a complete late model factory system . 

Let me know what you think ?


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