Brake Master Cylinder And Hydraulic Brake Servo Overview: Notes
WARNING:
With the introduction of the new Bosch 5 ABS/EDL systems (1996 m.y.REPAIR INSTRUCTIONS AND SAFETY PRECAUTIONS, BOSCH 5, FROM MY 96 ), the brake master cylinder has been modified. This change is cannot be recognized from the external shape. If the wrong master cylinder is installed, this may result in a loss of vehicle safety. Refer to the part number for identification.
WARNING:
- Brake master cylinder cannot be disassembled, and is not repairable.
- Use only new brake fluid. Refer to label on brake fluid reservoir.
- Brake line connections ABS HYDRAULIC UNIT OVERVIEW .
- Contact for brake fluid level warning switch
- Slide into recess in brake fluid reservoir to stop
Checking function of brake fluid warning switch/light:
- Up to 07.92 production: With ignition on, press forcefully on center of filler cap (diaphragm); brake fluid level warning light on instrument cluster comes on along with a warning buzzer
- From 07.92 production (diaphragm is eliminated): remove yellow filler cap with brake symbol; with ignition on, press down on visible filter screen by hand
- Slide into recess in brake fluid reservoir to stop
- Cover
- Seal
- Filter
- Brake fluid reservoir
- Fill brake fluid to MAX mark
- Connection for clutch hydraulic system on side
- Note label on brake fluid reservoir before topping off brake fluid
- Brake fluid total capacity: approx. 0.6 liters (0.63 qt.) in brake system
- Pressure line
- Pressure accumulator to hydraulic brake servo
- Before disconnecting, reduce operating pressure by pushing down brake pedal approx. 20 times with engine NOT running
- Hydraulic brake servo
- Do not operate brake pedal with brake master cylinder removed
- Check for leaks Checking hydraulic brake servo for leaks
- Return line
- Hydraulic brake servo to hydraulic fluid reservoir
- Lock nut
- Circlip
- Always replace
- Clevis
- Adjusting Adjusting clevis
- Pin
- Lubricate lightly before installing
- Seal
- Always replace
- Self-locking nut
- Always replace
- 25 Nm (18 ft lb)
- Rubber plug
- Moisten with brake fluid and press into brake master cylinder
- Nut
- 20 Nm (15 ft lb)
- Hose connections bracket
- Brake master cylinder
- Diameter: 25.4 mm (1 in.)
- Replace complete component if necessary
- Double bolt
- 25 Nm (18 ft lb)
- Brake lines
- Warning switch
- 20 Nm (15 ft lb)
- For monitoring pressure in hydraulic brake servo. If pressure drops to a value between 87 and 127 bar (1262 and 1842 psi), the warning light in instrument panel lights up and sets off an audible warning signal
- Thread into brake servo
- Check operating pressure of hydraulic brake servo HYDRAULIC BRAKE SERVO SYSTEM, CHECKING OPERATING PRESSURE
- Copper seal
- Always replace
- O-ring
- Always replace