Power Brake Unit: Disassembly
- Scribe marks on housings for reassembly reference and remove boot, front housing seal, vacuum check valve and grommet.
- Attach power unit front housing to holding fixture base (J-22805-1) and clamp base in vise with power section up.
- Place a spanner wrench (J-9504) on studs of rear housing. Press down and turn counterclockwise to unlock housings.NOTE: Do not put pressure on plastic power piston extension.
- Remove power piston bearing, return spring and power piston group. Remove piston rod and reaction retainer.CAUTION: Use care not to damage power piston assembly when removing reaction disc. Reaction disc must be replaced.
- Use awl, ice pick or similar tool to remove reaction disc. Remove reaction piston.
- Grasp assembly at outside edge of diaphragm support and diaphragm. Hold pushrod down against a hard surface. Use a slight force; or impact to dislodge diaphragm retainer.
NOTE:
Do not disassemble power pushrod assembly.