[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [New Search]

Re: [T3] Late front disc pads


On 17 Mar 2003 at 8:48, Mark Seaton wrote:

> Would these late type4 calipers work on there? That would mean longer time
> between pad changes if they do ;-) The rotors look healthy enough- a good
> 10mm thick or so. (didn't measure them but they just looked OK- will check
> later)

New late rotors are 11mm thick with a 9mm wear limit.

> I don't think they can be type4 calipers from what you've said as the
> pistons have the filled in middle for a compensating pin (little conical pip
> in the middle)

That certainly sounds right for type 3 calipers. I'm not sure about the type 4 
calipers, but Dave believes them to lack the pins, so they should have the 
simpler (and much more typical) pistons.

> By the way, do you know what the purpose of those little plates that locate
> in the pistons is for- I mean all I can say for sure is it stops the piston
> from rotating and keeps the cutout in the same position. BUT why have the
> cutout at all? My last car just had flat ended pistons that were free to
> rotate ( it didn't have dust seals either)

The theory is that the rotation of the rotor moves the thrust off center, so 
the cutout puts it back where it "belongs." I'm not sure that I quite 
understand this, but some cars had this feature and some didn't. Mercedes used 
it in the same era, for example.

The plates just force you to pay attention to how you install the pistons, and 
keep them from rotating in use, but I have no idea whether they would ever tend 
to rotate on their own.

I think all calipers have some kind of dust seal, but they often are hidden 
down inside, so they aren't as obvious. The seal is there to keep out water 
more than anything else, because the real problem is rust in this bore which 
will cause the piston to seize up.


-- 
*******************************
Jim Adney, jadney@vwtype3.org
Madison, Wisconsin, USA
*******************************

-------------------------------------------------------------------
List info at http://www.vwtype3.org/list | mailto:gregm@vwtype3.org


[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [New Search]