Power Brake Unit: Disassembly
- Remove pushrod boot, silencer, front housing seal, grommet and vacuum check valve.
- Scribe a mark on front and rear housings for reassembly reference. Attach front housing to suitable holding fixture. (Cadillac J-23456, all others J-22805-01).
- On Cadillac, press down on tool J-23456 and turn counterclockwise to unlock housings. On all others, place spanner J-9504 over rear housing studs, press down and turn counterclockwise to unlock housings.
- Remove power piston group, power piston return spring, and power piston bearing. Remove piston rod, reaction retainer and power head silencer.
- Grasp assembly at outside edge of divider and diaphragms. Hold with pushrod down against a hard surface. Use a slight force or impact to dislodge diaphragm retainer.
- Remove primary diaphragm, primary support plate, secondary power piston bearing, housing divider, secondary support plate and diaphragm and power piston assembly.