Ok, i know the brake fluid and clutch fluid are shared,my question is,do we ever need to change the fluid if so how do we know it needs to be change,and How,

 

RESEARCH.

The clutch and brake fluid are the same as you stated, no need to call it clutch fluid. They run off the master cylinder and slave cylinder of the car. The only time it needs to be changed is IF the fluid appears dark and murky in color.

 

Yes the hydraulic fluid reservoir is shared but due to the hygroscopic nature of brake fluid (has a tendency to absorb moisture) it is recommended to change it once every year or two for to maintain optimal brake performance. YMMV.