1.A 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 of air pressure / vacuum to be provided meaning actions of the 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: 1397220291 pump part numbers:A2308000648, A2308000548, A2308000448, A220800348, A2208000648, A2208000748, A2208000548, A2208000848, A2208001148, A2208001248, A2208000948.Fitment:For SL- (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 S- (W220) 1998-2005S280, S320CDI, S320CDI L, S350, S350 L, S400CDI, S430, S430 L, S500, S500L,S500 4-, S600L, S55 , S55 LFor - (C215) 1999-2006CL500, CL600, CL55AMG, CL63AMG, CL65AMGMaterial:ABSColour:blackPackage Contents:1 * Motor ImpellerOnly the above package content, other are not included.Note: Light and different displays may cause the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.