Gas locker leaks - check rubber seal
Pressure valve on water supply set incorrectly giving low water pressure through taps .
Front position lights letting water in.
I had a 510/4 1999, a lovely van which we kept for 7 years. Only trouble was floor delamination by the kitchen and in the bathroom. The floor went up and down when you bounce on it. Fairly easy fix by the dealer though.
Amazing family weekend with old steam engines, classic car displays, market stalls, and full catering and bar. And camping on site - Save £25 by booking in advance.