Often all that makes the calipers left or right is the bleeder valve
position. Air rises in the fluid, so to remove trapped air out of a
caliper it helps to have the bleeder valve at a high spot. In many brake
pairs the same caliper casting is used for both sides, with 2 cast in
bosses available for drilling a bleeder hole and only one hole is used,
making it a left or right. Sometimes both are drilled and threaded but a
proper bleeder valve is only installed in the hole that was intended to
be highest. If you put a proper bleeder in both holes you could make the
caliper interchangeable, left or right. This assumes symmetry in the
rest of the caliper, like the position of the threaded hole for the
brake line. Sometimes there are cast in 2 bosses for that as well and
only one gets drilled and threaded, again making it a left or right on
that basis.

Mark

Courtney Hook wrote:
> So I'm eyeballing these two rebuilt ATE calipers that came with different part no's and I can't tell what makes them different??? They appear to be identical as to up or down, so either left or right? Are they interchangeable? These also fit the early vanagons, so I thought I'd post it to the vanagon list as well.
> Thanks,
> Courtney
>