Master Cylinder: Disassembly
NOTE:
If master cylinder is to be put into a vise for disassembly, only put mounting flange in vise. Do not clamp on cylinder or reservoir.
- Drain all brake fluid from master cylinder and clean outside of master cylinder before disassembly. Remove reservoir cover and gasket. On aluminum master cylinders place a pry bar between master cylinder body and reservoir. Pry up until reservoir can be removed.
- Depress piston and remove stop screw, if equipped. Remove lock ring from groove in end of bore or retainer and screw. Remove rear (primary) piston assembly.CAUTION: Do not disassemble rear piston assembly or change adjustment of screw.
- Remove front (secondary) piston with air pressure. If air pressure does not work, use wire hook to pull piston out end of cylinder. Remove front piston spring if it did not come out with piston. Remove splash seal and retainer outside rear of cylinder, if they are used.
- If tube seats are not re-usable, remove them by threading an easy-out tool firmly into seat and tapping tool and seat out.
- Another method is to drill a 13/64" hole through each seat. Then tap hole with a 1/4-20 tap. Screw a tubing nut into outlet. Then insert a 1/4-20 machine screw (with washer) through nut and into tube seat. Hold screw from turning. Unscrew the tubing nut to remove seat.
- If tube seats are removed, remove check valve and spring from drum brake outlet.