Running through the engine bay of an MX5 NB (1998 - 2000) are several hoses that conduct coolant between the block, radiator and auxiliary systems. They are constantly subjected to heat changes, pressure build-up and vibration, which can cause rubber to harden after years or develop small hairline cracks. Often a problem starts with slight swelling around connection points or a hose that feels less smooth than before. When the radiator and other front cooling parts also remain healthy, the flow remains nice and constant.
