Update:

Firstly - Thanks to all who have offered advice. I've finaly had a chance to get my head under the bonnet - and (using the screw driver trick) I can clearly hear the vacuum pump clicking away like a busy bee.

I've had a look in the Hains and workbook regarding the vacuum pump change. It looks to me as it's disconnecting 2 electrical type plugs ontop of the pump, undoing 4 screws, replacing the gasket and wacking the new one back on.. is it really that simple or am i missing somthing here?

It all looks simple apart from the issue of getting the bloody thing back on, which I understand is a bit of an issue. Some say you have to TDC the engine, other just unbolt and replace with a key turn to move things about - others manage to get it off and on without any fusse.

Im pleased to here that you dont hear your turbo making a noise cos neither do I. Mine gets a spurt of power just before 2500rpm so it must be working....I hope

i hear my turbo all the time...and me disco drives like a tank....dont think its working really.

balls.