Friend bought used bike 4900 miles. Brake lever and clutch lever are aftermarket. The brake lever pulls all the way to the grip. It does stop but seems to not have enough pressues. I believe it is either the lever and or someone added dot 4 to the system. DOT 4 would attack the rubber and soften it up and make brake lever squishy. What color should DOT 5 fluid be. Why I ask is the 2 cans of 5 that i have are both purple fluid and the fluid in this bike is yellow.