1.8 TD? Diesels don't have dump valves because there's no throttle plate for the compressed air to get stuck behind...

If you did want to hook it up, you need a hose from the inlet manifold to the vaccum connector on top of the valve. The valve needs to be situated between the outlet of the turbo's compressor housing and the inlet manifold. The hose on the exit of the intercooler (if you have one) would be suitable.