An R50 mini has two bleed points for its cooling system - one is by the top of the radiator (left side) the other is located at the back of the engine between the battery tray and the exhaust manifold - the 2nd bleed point links two hoses and is a hard plastic component. Is there a more durable way to connect these two pipes and thus loose the (fragile) plastic fitting - perhaps with a piece or two of copper pipe - is there an upgrade for this component ?, if not what size copper pipe would be required to replace it (8, 10 or 15mm)