Vacuum Pump Rebuild Kit

[Duecento]

Where is the best (cheapest) place to find a rebuild kit D24 vacuum pump? Mine has a valve that has gone bad.

[Volvoist]

I believe that the kits are NLA, at least through Volvo. Pierburg used to make kits for these. I know Tom Bryant rebuilds them with some sort of modification. Worst case scenario, get a used pump. I may have a good used one I could sell, but I would need to verify that I do have one...