I changed the front pump seal on a Bosch diesel pump on the car today. 86 Golf 1.6 . 4 hours, bending over the front of the car. I've seen it done , but never attempted it. I thought it was a new fuel problem, but it looks like it just scrubbed itself from vibration. The job sucked, but the gasket kit was only $25 bucks. And that beats buying a rebuilt pump.