Brake Booster

Brake Booster

Booster Leak Test

A Vacuum gauge

B Tube joint adaptor

C Vacuum joint tube A

1. Install the special tools as shown.
2. Start the engine, adjust the engine speed with the accelerator pedal so that the vacuum gauge readings show 300 – 500 mm Hg (11.8 – 19.7 in Hg), then stop the engine.
3. Read the vacuum gauge.

If the vacuum reading decreases 20 mmHg (0.8 inHg) or more after 30 seconds, check the following parts for leaks.

• Check valve.
• Vacuum hose, pipe.
• Seals.
• Brake booster.
• Master cylinder.

CAUTION: Do not try to disassemble the brake booster. Replace the brake booster as a complete assembly.

A Bleed valves

B Pressure gauges

C Pressure gauge attachment C

D Pressure gauge joint pipe

E Pressure gauge joint pipe

1. Install the vacuum gauge as shown in the leak test.
2. Connect the oil pressure gauges to the master cylinder using the attachments as shown.

Note: Item E will vary depending upon whether the car is fitted with ABS, see TOOLS.

3. Bleed air through the valves.
4. Start the engine.
5. Apply a pressure of 200 N (20 kg, 44 lbs) to the brake pedal and, referring to the appropriate table, check that the pressure gauges register the correct pressures at the specified vacuums (as indicated on the vacuum gauge).