Disassembly and Assembly

Fig. 21 Exploded View Of Bendix Dual Master Cylinder Used w/Disc Brakes:

Fig. 22 Master Cylinder w/Fluid Control Valve Installed. Front Wheel Drive Models:

Disassemble

1. Remove cover and diaphragm then drain brake fluid from master cylinder, Fig. 21.
2. On front wheel drive models, using a screwdriver, pry up on reservoir and remove primary port from master cylinder, Fig. 22.
3. Rotate reservoir out of way and remove sealing grommet from master cylinder casting.
4. Using a socket, remove fluid control valve.
5. On all models, depress primary piston and remove snap ring from retaining groove at open end of bore.
6. Remove primary and secondary piston assemblies from master cylinder. If secondary piston does not readily come out, apply air pressure to secondary outlet port to remove.

Inspection

When disassembled, wash all parts in clean brake fluid only. Use an air hose to blow out all passages, orifices and valve holes. Air dry and place parts on clean paper or lint-free cloth. Inspect master cylinder bore for scoring, rust, pitting or etching. Any of these conditions will require replacement of the housing. Inspect master cylinder pistons for scoring, pitting or distortion. Replace piston if any of these conditions exist.
If either master cylinder housing or piston is replaced, clean new parts with clean brake fluid and blow out all passages with air hose.
Examine reservoirs for foreign matter and check all passages for restrictions. If there is any suspicion of contamination or evidence of corrosion, completely flush hydraulic system as outlined below.
When overhauling a master cylinder, use all parts contained in repair kit. Before starting reassembly, dip all cups, seals, pistons, springs, check valves and retainers in clean brake fluid and place in a clean pan or on clean paper. Wash hands with soap and water only to prevent contamination of rubber parts from oil, kerosene or gasoline. During assembly, dip all parts in clean brake fluid.
Inspect through side outlet of dual master cylinder housing to make certain cup lips do not hang up on edge of hole or turn back, which would result in faulty operation. A piece of 3/16 inch rod with an end rounded off will be helpful in guiding cups past hole.
When overhauling aluminum master cylinders, carefully inspect master cylinder bore for corrosion. If corroded, replace master cylinder. Do not hone or use abrasives on the bore of these cylinders.

Assembly

1. Install secondary piston assembly into bore, spring end first.
2. Install primary piston assembly, spring end first.
3. Depress primary piston and install snap ring.
4. On front wheel drive models, install fluid control valve and torque to 97-115 inch lbs.
5. Lubricate new grommet with brake fluid and install in primary port.
6. Install reservoir in new grommet.
7. On all models, fill and bench bleed master cylinder. Refer to Brake Bleeding.
8. Install cap and diaphragm on master cylinder reservoir.