Err Where is my fuel Pump ?

I have a mk1 1.8i cabby, and i thought the fuel pump was underneath the rear seat, took this out and found only the fuel sender unit.
The pump is slowly becoming more and more noisey, so I think either the filter is blocked, or its wearing out. Could somone please tell me where it is and if its worth taking out to clean the filter around it (if it has one)
Thanks
Jon

Ther eis a lift pump/sender unit under the rear seat and a main fuel pump unter the car, next to the fuel tank on the drivers side.

The lift pump has a filter in th that can get blocked if you've had a rusty filler nect at some point. The main pump sometimes has a small filter in the fuel line that connects to the fuel pumps inlet.

There is also some large filter thats tucked up on top of the fuel tank. It doesn't usually cause problems but has been known to.

There is also the main filter in the engine bay. Has that been changed recently?

Cheers,

Ross