This is a clutch master cylinder rebuild for an early 1980's Honda motorcycle. The hydraulic clutch system has three major components, the clutch master with the clutch lever on the handlebars, the clutch slave which actuates the clutch pack in the transmission and the clutch pack itself. When the clutch pack wears out, the engine will have trouble transmitting power to the rear wheel and when bad enough, the engine will spin without driving the rear wheel at all. When the master or slave no longer function correctly, the opposite is true as the clutch never seems to actuate fully and changing gears becomes difficult and rough. The clutch slave will usually fail first as all of the debris in the system will fall to the bottom where the slave is and gum it up causing it not to function correctly. When the slave is rebuilt, the master should also be rebuilt as it is usually the source for much of the debris that fouled the slave cylinder.
This rebuild is also applicable for the brake master cylinder as the arrangement is very similar. The only special tools needed for this job is a Japanese Industrial Standard (JIS) screwdriver which looks very similar to a Phillips screwdriver, but the star profile is different enough that a Phillips screwdriver will likely strip a JIS screw head, and the other special tool is long nose right angle snap ring pliers. The master cylinder piston assembly is held in place with a snap ring, but due to the recess it is located in, the special snap ring pliers are needed.
Tour Max - Master Cylinder repair kit (clutch) MSC-101
Tour Max - Master Cylinder repair kit (brake) MSB-102
A motorcycle will likely have either a cable clutch or a hydraulic clutch which operates on the same principle as motorcycle front hydraulic brakes. Using an Archimedes principle that stipulates a liquid can be used to transfer equal force over a distance since liquid can not be compressed. As equal volumes are displaced at each end of the system, the force can be amplified as a long stroke small bore piston can be translated into a short stroke large bore which is what motorcycle hydraulic clutch and brakes use increase force at the actuating end.
29 май 2021
