DId this exact job, The problem is that the seal is done through good machining with rubber only working to support the good tight machine fit. I had no luck resealing mine. It slowed down but did not stop. I found a used pump for $100 and popped it on, now the engine is dry as a bone. I talked to my mechanic and he said when these usually leak from the front seal they are almost impossible reseal. The rear seal is easier to do and can be rebuilt more sucessfully.
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)