sme problem happend with mine, im guessing its leaking out the actuall shaft wer the pullys on
its the seal thst gone by the bearings, cant be fixeed, u gt to replace the pump, mke sure u get a metal replace ment one as it wil last longer
all u need to do wen chnging the belt is to lock it in position, u get specialised tool or use sumthing prehistoric like a wedge lol ull need to chnge the tensioner aswell just tbs, simple job then to remove a few 8mm nd 10mm bolts and the water pump will just slot off nd themn put new one on,
thers a how to guide on vw vortex i believe lol