I am working on my grandmothers 1987 KLF 300 Bayou. The brake lever had to be pulled all the way in to get any braking force at all. Once I drilled out the screws holding the cap I realized what was wrong... seventeen years of gunk. I want to replace the seal inside but I can't figure out how to get the pump out of the assembly. There is a dust boot covering the piston. I don't see any c clips or anything else that would prevent it from just being pulled out. Any ideas... the online parts store wants $250 for a complete master cylinder.