i’ve just bought a new bike with shifter and brake units together on the handlebars. i want to replace the brakes with hydraulics from my last bike (new bike has cable brakes), however i don’t know if this is possible.
the old bike has separate shifter and brake units, and is 3x9 gears, the new bike is 3x8 gears.
I asume you have the complete brake system from you previous bike (Calipers, hoses and levers)
In order to complete the installation you would need to buy a set of 3x8 independent shifters, so you would discard the shifter-lever combo units. 3x8 Shifters should not be too costly, just make sure they are compatible with the ones you have currently installed.
There are some shifters than can be bolted into a specific model of brake lever and it may look like they are a single integrated unit, but I seriously doubt this would be the case (I remember some 15 years ago, Avid had a "match maker" that allowed this integration. I do not now for sure if the shifters could be installed independently but sure those would allow to replace only the brake lever or only the shifter in case one of them broke)
