Roomster
| Summary of components of brake servo unit, master brake cylinder up to MY 2010 |
Note| The complete master brake cylinder and brake servo unit can be replaced independently of one another. |
| 1 - | Brake servo unit |
| q | removing and installing → Chapter |
| q | Assignment → Electronic Catalogue of Original Parts |
| q | on petrol engines the required negative pressure is drawn from the induction pipe |
| q | Diesel engines are fitted with a vacuum pump or tandem pump for fuel and negative pressure supply |
| Inspect proper operation: |
| – | With the engine off press down brake pedal repeatedly with force (this reduces the pressure already present in the device). |
| – | Now hold the brake pedal in brake position using a medium foot pressure and start the engine. If the brake servo unit operates perfectly the brake pedal must yield noticeably under your foot (servo boost takes effect). |
| q | if there are faults replace completely |
| q | Non-return valve (in vacuum hose); Functional test → Chapter |
| q | disconnect from brake pedal or clip onto brake pedal → Chapter |
| q | Non-return valve in the vacuum hose of the tandem pump for fuel and vacuum supply → Chapter |
| 2 - | Brake fluid level warning contact -F34- |
| q | cannot be removed or repaired |
| 3 - | Cap |
| 4 - | Brake fluid reservoir |
| q | removing: |
| – | Drain brake fluid. |
| – | Press out retaining pin from the lateral catches of the brake fluid reservoir and master brake cylinder. |
| – | Pull brake fluid reservoir upwards out of the plugs. |
| q | Installing: |
| Installation is carried out in the reverse order. |
| – | Fill up with new brake fluid. |
| – | On vehicles without ABS or with ABS, ABS/TCS BOSCH 8.0 bleed brake system → Chapter |
| – | Perform basic setting: |
| t | with vehicle diagnosis, measurement and information system -VAS- → Chapter |
| 5 - | Plugs |
| q | moisten with brake fluid and press in brake fluid reservoir |
| 6 - | Self-locking nut, 20 Nm |
| q | replace after each installation |
| 7 - | Master brake cylinder |
| q | cannot be repaired, replace completely in the event of faults |
| q | Check tightness → Chapter |
| q | removing and installing → Chapter |
| q | Assignment → Electronic Catalogue of Original Parts |
| 8 - | Retaining pin |
| q | to secure brake fluid reservoir at brake master cylinder |
| 9 - | Sealing ring |
| q | replace after removal the master brake cylinder |
| 10 - | Plugs |
| 11 - | Vacuum hose |
| q | insert with brake servo unit |
| 12 - | Cap |
| q | check for firm seating |
| 13 - | Self-locking nut, 28 Nm |
| q | replace after each removal |
| 14 - | Gasket |
| q | for brake servo unit |
