If you see your vacuum pump (on the end of the camshaft) leaking oil, that oil is dripping unseen onto a tiny 3" long coolant pipe hidden beneath. The oil will rot the coolant pipe, and it will pop. Pissing all your expensive G12 all over your gearbox speed sensor, which will also likely go wrong...(no speedo, wobbly fuel gauge, disco fuel light and irritating low fuel bongs will follow).
The Seat (spanish take on a MK4 Golf with VW bits) has a wonderful sense of timing. Drove all round the Uk last month. Devon to Norwich, Lincoln, Chesterfield, Macclesfield, Peak District. Returning home on the motorway, just got dark, On comes the flashing red coolant light with it's associated bongs, 300 yards from the Gloucester Services slip (One of the better places to stop to).
With a lot of swearing, i managed to get a piece of 8mm fuel hose in as a stopgap and get home. But the hose spring clips are devils.
Looking up the part number for that hose, 1J0122447EP, it is an assembly of about 9 bits, 8 of which you won't need, for the bargain price of £100 ish. VW must sell loads....not! So off to the scrap yard for some suitable replacement 8mm? coolant hose.
Fuel hose is oil proof, but will harden and crack with heat.
The vacuum pump oil seal is part no "038145345" , if the pump is leaking from it's two halves, you need a 76mmx2.5mm viton "O" ring, google will show you what to do. Mine is now nice and oil tight.
ASV, 218k miles & counting.
