A common problem on the GL1800 is air gets in the line for the hydraulic preload adjuster. So we recommend bleeding the preload adjuster and topping it off with fresh oil plus installing our new Steel Braided Line. The steel braided line replaces the poor quality OEM plastic line. The OEM line tends to well over time which allows air in the system. With our steel braided line the system will be sealed much better very similar to steel braided lines in a brake system.