LEMON Manuals: Even more car manuals for everyone
Home >> BMW >> 1985 >> 528e Automatic >> Repair and Diagnosis >> Brakes >> Mechanical - Hydraulic >> Disc & Drum >> Testing >> Power Brake Unit

Power Brake Unit

NOTE: The following tests are in BAR pressure units.
  1. With engine off, pump brake pedal about 20 times with a force equal to full stop braking action (45 lbs./200 N) to discharge the hydraulic reservoir. Pull off wires and remove warning switch.
  2. Connect Brake Pressure Tester Adapter and Pressure Tester (32 4 000 and 34 3 160) to brake booster. Shut off both control valves. Start engine and check pressure regulator and brake booster for hydraulic leaks.
  3. While engine is running, observe pressure meter. Stop engine after reaching upper switching off pressure.
  4. If reservoir pressure (pressure meter reading) drops more than 71 psi (5 BAR) within 5 minutes, disconnect return line on pressure regulator. If fluid leaks from return line bore in pressure regulator and pressure regulator leaks, replace pressure regulator.
  5. If there are no fluid leaks and reservoir pressure still drops, brake booster has an internal leak and must be replaced.
scientia non olet · About LEMON Manuals