GBG Tap Seal - Bottom Cap This is the bottom red rubber seal. If you notice that your machine is leaking/dripping from tap, this is most likely the part that needs replacing. This part is said to look like a mushroom shape. It gets inserted into the white plunger piston. This part suits the older GBG models with the white piston plunger that has a rubber O-ring and Bottom Tap Seal. The Bottom Tap Seal appears as the bottom seal which gets inserted into the plunger (as seen in the picture above). Colour: Red Material: Rubber Manufacturer Part Number: SL3GS12044A Position Number in Exploded Diagram: GT14 SKU: 1704312044