Power Brake Unit: Removal
- Siphon brake fluid from master cylinder reservoir. Remove left portion of lower dash panel. Remove operating rod clevis pin from brake pedal arm. Disconnect and plug hydraulic lines at master cylinder, including clutch hose.
- Disconnect vacuum hose from power brake unit (hydraulic lines on 735i). Remove power brake unit mounting bolts. Remove power unit/master cylinder assembly from vehicle. Separate master cylinder from power brake unit.
NOTE:
On 535i, 635CSi and 735i models, power steering pump also supplies hydraulic pressure through hydraulic accumulator to the power brake unit. If power steering fails, there will be sufficient pressure in the hydraulic accumulator to provide a few brake applications with full power.