[T3] Type 3 front break calipers

[Jim Adney]

On 21 Mar 2017 at 2:03, Daniel K. Du Vall wrote:

> Sorry should have been more clear about the bump. I was referring to a
> casting bump that will be found on aftermarket replacements on the
> side that faces the rim. I have a set of original Bug clippers that
> have no casting bump and a set of new ones that do. The set I have
> that are in question do have duel blead valves as well as a tube that
> connects each side of the caliper. 

I'm not sure, but I suspect that external casting features can vary a lot, even with 
OE calipers. For example, You can find at least 3 different kinds of bolts that 
hold the caliper halves together. I think they just represent different eras of 
production, some of which may even be Brazilian. There WERE good Type 3 
calipers made by ATe in Brazil, but no longer. Only Type 1s are made today.

As far as a tube that connects the 2 sides of the caliper, that doesn't sound 
remotely OE. I've never seen anything like that.

> Now that you mention it I think the ones on the 72 only have a single
> blead valve will verify that in the morning. If it's true I probably
> have the wrong ones on there to begin with yikes. I will take pictures
> of the ones I have and post them. 

All the late OE Type 3 calipers have dual bleed valves. All the early OE ones 
have single bleed valves. You can find other variations made for other cars. 
Current Type 1 calipers have dual bleed valves and lack the internal 
compensating mechanism. That means they can be either L or R, but they have 
40 mm pistons, yielding 10% less braking force for the same pedal pressure, 
thus also changing the F to R braking balance.

If you have a caliper that's right except that it needs another bleed valve, I can 
add it, but that costs $$$.

Ate made lots of calipers for lots of different cars. They often did this starting 
from the same castings, so you can't always tell what you have until you 
measure the pistons. I've seen calipers that look like ours that have 37, 38, 40 
and 42 mm pistons.

There's also the late Type 4/914 calipers that look like our late calipers, but they 
have a wider pad pocket and they won't work on our late cars because the rotor 
hits the casting. They're easy to confuse unless you have the other style at hand 
for compartison. You can shim them, but IMHO that's a very iffy thing to do.

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