> Another response indicated that the function was incorporated into the
> casting in the later part. I certainly can't fault its fit or function,
> both are fine.
>
> George
VW discontinued the residual pressure valves starting with the 73 model year. Instead the drillings in the brake line ports were sized to the smaller spec of the disc brake master cylinder. This is why disc brake conversions should never utilize the pre 73 drum master cylinders.