I am not familiar with the 300td suspension, however, I believe it is similar to mine in a 560. THere is a resivoir in the front and to lines on in one out. the pump is on the block on my car but yours may well be belt driven they had two versions I believe. The lines on my suspension are all metal and go back to the accumulators then to the shocks. I can't imagine yours being much different. What colour is the fluid?
2005 320 CDI
2006.5 VW Jetta TDI
1991 560SEL (179000 Sold)
1972 280SEL 4.5 ('The Lead Sled' 320000 miles when sold.)
1972 220D (225000 when sold)