1.A graphite impeller within the vacuum pump fails causing vehicle faults.2.Sometimes water ingress can cause problems with these pumps, often however the impeller on the spindle of the motor can break or shatter over time.3.A broken impeller will cause a lack of air pressure / vacuum to be provided meaning actions of the PSE pump will be inhibited.4.It can also lead to a jammed motor which will lead to the pump blowing the 20A fuse and shutting off.fot motor part number: 1397220291Mercedes pump part numbers:A2308000648, A2308000548, A2308000448, A220800348, A2208000648, A2208000748, A2208000548, A2208000848, A2208001148, A2208001248, A2208000948.Fitment:For Mercedes Benz SL-Class (R230) 2001-20111st gen: 2001- 2006 - SL350, SL500, SL600, SL55AMG, SL65AMGFacelift 1: 2006 - 2008 - SL350, SL500, SL550, SL600, SL55AMG, SL65AMGFacelift 2: 2008 - 2012 - SL280, SL300, SL350, SL500, SL550, SL600, SL63AMG, SL65AMGFor Mercedes Benz S-Class (W220) 1998-2005S280, S320CDI, S320CDI L, S350, S350 L, S400CDI, S430, S430 L, S500, S500L,S500 4-Matic, S600L, S55 AMG, S55 AMG LFor Mercedes Benz CL-Class (C215) 1999-2006CL500, CL600, CL55AMG, CL63AMG, CL65AMGMaterial:ABSColour:blackPackage Contents:2 * Motor ImpellerOnly the above package content, other products are not included.Note: Light shooting and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.