This Clutch master Cylinder booster amplifies the Pressure pRoduced by the mechanical Pressure pRoduced by your foot And the Clutch Pedal. When these go bad they can pRoduce a miriad of problems but typically it results in the Clutch Pedal that is much harder To depress or a lack of Clutch disengagement. It can also pRoduce a Pedal that feels spongy. The issue is that a faulty master And Slave Cylinder can pRoduce the same results. These are a discontinued part With very few left in sTock.