Wasn't paying attention. The inside diameter in the direct drum where the metal sealing rings for the pump ride was scored pretty deeply on my C4. I cut it with a boring bar until it was smooth. I then checked that the rings would still seal before assembling.Thanks Guys . I might give it a go and see how it turns out . I have already bought a replacement so this one is spare , just a shame to throw it away if can be saved .
Adrian i only wish they were that cheap here . A good used drum costs 80 bucks here + 15 for a courier to deliver .