These things dont last forever. The baking 200-degree temperatures on top of a glareshield mean youll likely be faced with a repair or replacement. Generally, the main part that fails (ultimately leaking) is the rear rubber expansion/contraction diaphragm. Since the fluid in the compass needs room to expand and contract with temperature changes, a sealing membrane keeps the fluid inside. These simple devices arent packed with components. Typically, it takes just four small screws to expose the diaphragm on the rear compass housing.