My Bosch washing machine is leaving sludge like

Make sure the draw is 100% clean inside the draw compartment to if the draw is all clean next thing to cheak is the rubber door seal make sure it is clean all the way round next thing to cheak is the pump at the front of the machine pull down the cover and undo the the pump cover by tuning anti clock wise water will come out when you cheaked it is 100%clean put it back together if you get stuck read manual if all toughs things are clean or bean cleaned. do a 90 again with washer cleaning detergent with you can buy at the super market hope this helped.